There are two film versions of A Raisin in the Sun: the 1961 version starring Sidney Poitier and the 2008 version starring Sean Combs. My response will reference the 2008 film.
The 2008 film follows the play very closely; however, there are a few differences. At the beginning of the film, Lena is shown at her last day of work. The child whom Lena looks after is sad that Lena will no longer be working for them. This is not seen in the play--the reader simply knows that Lena works as a maid for a white family.
Another difference occurs when Walter begins skipping work. In the film, Walter's employer calls and Lena answers the phone stating that Walter is not home. She is told that Walter did not show up for work on that day. In the play, however, Ruth answers the phone when the employer calls and Walter is in the bedroom lying down. Ruth is told that Walter has been absent from work for three days.
Finally, a major difference between the film and the written play is the appearance of Mrs. Johnson. In the written play, Mrs. Johnson serves as a foil character for Lena. She has been removed from the 2008 film version.
One of the differences between the play and movie version of A Raisin in the Sun is that the entire play takes place in the Youngers' living room, while the movie also shows the family's bedrooms, the bar where Walter hangs out, and Walter's workplace. Because there are locations in the movie that are not in the play, some of the scenes are moved. In the play, the audience merely hears about Walter's job, but in the movie, Walter is shown working as a chauffeur. In addition, Lena, or Mama, is shown speaking to Walter in the bedroom about the liquor store in the movie, while this scene takes place in the living room in the play. Later, Mama gives Walter money in their apartment in the play, but this scene is moved to the bar in the movie. In the movie, the bar where Walter goes is known as the Kitty Cat, while it is called the Green Hat in the play. In the play, the mailman comes to the house to deliver the letter with the insurance money, while in the movie, Travis runs up to the mailman outside the apartment. Finally, Beneatha cuts off her hair in the play, while she does not do so in the movie.