The authors discuss stage models of gay and lesbian identity formation first proposed during the 1970s within affirmative approaches to homosexuality. The process of developing homosexual identity is characterized here with linearly ordered stages distinguished around major developmental events leading to new self-definition. Among many stage proposals the authors have chosen and presented two: by Vivienne Cass and Susan McCarn with Ruth Fassinger. The presented models were analysed in terms of their usefulness in therapeutic practice aimed at promoting the formation of gay identity, for which they have been originally designed. An important part of this discussion is evaluation of the accuracy of developmental process descriptions contained in stage models.