Act I
Men in White opens in the library of a metropolitan hospital where members of the staff are gathered. Hochberg, the chief of the surgical staff, and Ferguson, an intern, are discussing Mr. Hudson, a wealthy patient who is about to be discharged. Ferguson is engaged to Hudson’s daughter Laura. After the couple marry, they plan to go to Vienna, where he will study surgery. The following year, he will return to work with Hochberg. Ferguson finds out that he needs to stay at the hospital with one of his patients. He agrees to break his evening plans with Laura. Then an emergency calls him to the operating room.

Scene ii opens in Hudson’s hospital room, which Hochberg and Laura soon enter, and they discuss the demands of the medical profession. Hochberg points out that the next five years are crucial to Ferguson’s career as a surgeon. After Ferguson joins the group, he and Laura are soon left alone. When he tells her that he has to cancel their plans for that evening, she gets very upset. She tells him that she cannot put up with his demanding schedule much longer. She threatens to break their engagement if he does not promise to forgo his studies with Hochberg and instead open a private practice after returning from Vienna. Before they can discuss the situation in depth, Ferguson has to run off to attend to an emergency.

Ferguson has been called to see a young diabetic who has lost consciousness. When he arrives at her room, he finds the girl’s own doctor, Cunningham, is already there. The two doctors disagree on the diagnosis. Cunningham believes the girl has slipped into a diabetic coma and orders insulin, but Ferguson thinks she has gone into shock. The men argue, and when Cunningham hesitates, Ferguson wrests the hypo of insulin from him and takes charge of the patient. His diagnosis proves correct and the patient recovers, but Cunningham threatens to report him nonetheless. After Cunningham leaves, Ferguson offers to give the nurse, Barbara, some medical notes for an exam. Before moving on to his next patient, he promises to leave the notes on the first floor for her.

Later that evening, Ferguson, who has retired to his room, has a brief conversation with Laura in which she asks him to make a decision about their future. A former student of Hochberg’s named Levine, who is now in private practice, enters. He wants Ferguson to check on some specimens from his wife that he left with Hochberg. Ferguson arranges for the results to be sent down. While they wait, Levine tells the younger man that he once had the chance to work with Hochberg, but instead he married and went into practice to support his wife. His life since then has been exceedingly difficult, and he wonders if he made the right decision. Ferguson explains that being a doctor has always been the only thing he wanted to do, even if he has to put aside personal pleasures to accomplish this goal. The orderly then brings in the lab results, which confirm that Levine’s wife has tuberculosis.

After Levine leaves, Barbara arrives for the notes, which Ferguson forgot to leave for her. Barbara volunteers to go speak with the hospital administrators if Cunningham tries to get Ferguson in trouble. They talk briefly about patients and the hard work the hospital requires. Ferguson kisses Barbara but then tells her that he is going up to the ward and she had better leave. However, after he has departed, she sits on the bed, waiting for him to return.

Act II
Three months have passed when act 2 opens. The hospital committee is meeting to discuss the perilous financial situation of their institution. Hudson is prepared to join as a new trustee and will provide the hospital much-needed funds. In return for his donation, the hospital needs to offer Ferguson an associateship. Hochberg objects that such an appointment is not possible because Ferguson is not yet qualified for the job. The other members of the committee do not see the problem because, with Hudson’s connections, they believe Ferguson can develop a lucrative practice. Much to Hochberg’s surprise, Ferguson already has informed one of the committee members that he is delighted with the plan.

Coming from their wedding rehearsal, Ferguson and Laura enter the library in high spirits. Ferguson tells Laura that he is looking forward to the associateship appointment. Although he hopes to talk to Hochberg before the committee brings it up, when Hochberg enters the library, Ferguson realizes that he is too late. Ferguson and Laura try to make Hochberg understand that they want to have time for each other, but Hochberg remains unhappy with the decision. Their conversation is interrupted by the news that Barbara is ill with a serious infection resulting from an illegal abortion. She may need surgery. Ferguson heads out for the operating room. After he leaves, Hochberg suggests that Laura observe the surgery. He hopes it may make her understand how important Ferguson’s work is. She agrees.

As Barbara is being prepared for surgery, Ferguson asks one of the nurses why Barbara never came to him for help. He says that he would never have let her go to a dangerous abortionist. Barbara is now completely alone, for she has no family and she will be thrown out of the nursing program. After examining Barbara, Hochberg orders a hysterectomy as the only hope of saving her life. The doctors head for the operating room. One of the nurses brings Laura into the operating room, and then Barbara is wheeled in. When Ferguson approaches Barbara, she asks him to take care of her and tells him that she loved him. Laura realizes that Ferguson is the one who got Barbara pregnant, and Ferguson admits to the affair. Starting to cry, Laura leaves the operating room, and the operation begins.

Act III
The next day Hochberg finds Ferguson in his room. Ferguson stayed up all night with Barbara, and now her temperature has fallen. Ferguson tells Hochberg that he plans to ask Barbara to marry him—Laura refuses to speak to him and Barbara is alone in the world with little future. Hochberg questions Ferguson’s decision, pointing out the difficulties of going into private practice. Hochberg cannot convince Ferguson to change his mind, however. Ferguson even declares that he will give up medicine, if he must, to support Barbara. Then Laura comes in to see Hochberg. Ignoring Ferguson, she tells Hochberg that she is planning to sail to Europe that evening. Hochberg reveals Ferguson’s plans to marry Barbara and then leaves. Ferguson and Laura talk about what has happened. Ferguson says he has no choice; he is responsible for the destruction of Barbara’s life so he must help her. Laura admits that she was acting selfishly by making Ferguson give up his dreams of being a surgeon. She admits that she stills loves him. Then Hochberg returns with the news that Barbara has died. Laura wants Ferguson to go with her and talk things over. Ferguson refuses, saying that he belongs at the hospital. He has made the decision to devote himself to medicine.