Although literature for young adults is seldom reviewed widely or in depth (unless the author is relatively well known), The Friends received several favorable reviews. Elizabeth Haynes in Library Journal described the novel as powerful and praised the realism of its characters, setting, and language. A Kirkus Reviews critic also found The Friends memorable, particularly because of the complex development of Phyllisia's character as she learns to cope with the difficulties of life in Harlem. The reviewer admired the skillful presentation of the comparisons between Phyllisia and her father, concluding that she is a character "worth knowing even when she's least lovable.’’ Both journals included the novel among their selections for the best books of the year.

In particular, Guy received praise for her sensitive and perceptive handling of potentially controversial subject matter such as prejudice and racism. In addition, The Friends was mentioned for its pioneering role in the development of several strong, black female characters since up until the 1960s books for children and young adults seldom employed minority characters in prominent roles. In the opening paragraph of her review in the New York Times, Alice Walker noted that novels such as The Friends filled a gaping void, providing sustenance for black adolescents who had been "hungry for heroines.’’ The struggles that Phyllisia goes through in having to deal with hostile classmates, a racist teacher, a cold and domineering father, and, most tragic of all, a dying mother create a vivid portrait of the growth of a young girl struggling to survive in anew country. Walker commented on the novel's valuable insights into this process of growing up: "And so begins the struggle that is the heart of this very important book: the fight to gain perception of one's own character; the grim struggle for self-knowledge and the almost killing internal upheaval that brings the necessary growth of compassion and humility and courage, so that friendship (of any kind, but especially between those of notable economic and social differences) can exist.’’

All reviews, however, were not favorable. The novel was criticized for plot weaknesses and stilted dialogue. M. R. Hewitt in The Junior Bookshelf found it hard to sustain interest in the book because the characters were so unappealing: ‘‘... one a rather priggish girl from a proud West Indian family, the other a sluttish, thieving but ever loyal and loving drudge struggling to keep her parentless family together.’’ While the review in Booklist found the novel's characterizations complex and admired the realistic portrayal of life in Harlem, the overall conclusion was negative: "The plot is nonexistent, the dialog is sometimes awkward, and several scenes are jolting.’’

Over the years, critical acclaim for The Friends has increased. As the other two books in the trilogy emerged, the full range of Guy's portrait of family and neighborhood became clearer and the depth of her characterizations received more notice. In 1980, the American Library Association declared it one of the best novels of the previous fifteen years. When the English Journal asked several teachers at the Virginia Polytechnical Institute to select a handful of young adult novels that they believed would become "classics,'' they chose Guy's trilogy for its expert plotting, perceptive presentation of characters, and skillful use of language and idiom. In their opinion, the three books raised the standards of novels for adolescents.

Interestingly, the novel has been part of the standard curriculum in the United Kingdom since the 1970s. There is even a magazine devoted to explaining the neighborhood where Phyllisia and Edith live. Guy points out the irony of this in an article in Horn Book Magazine: "Young people in England can speak with authority about a place called Harlem in America, of which Americans—some living a mile away—know nothing. A young Londoner can describe conditions in American 'inner cities'—places which Americans drive miles to avoid, even as they discuss how to bring 'democracy' to El Salvador and Nicaragua.’’