The issue of identity is one of the main issues that encounters man in each culture. Identity is a set of behaviors, emotions, and thought patterns which are unique to every individual that define him as a member of a certain group. Identity is shaped by race, ethnicity, religious beliefs, language, physical features, childhood experiences, sexual preferences and culture. Moreover, identity is usually recognized during adolescence or early adulthood in which both positive and negative features are essential in the development of individual identity. However, an identity crisis is the failure to establish identity during that age. In addition, an identity crisis is not only concerned with matters such as ethnicity or religion as it is also concerned with inner conflicts, search for identity, west vs. east, old Vs. modern. The diversity of identity in the American culture is expressed in many literary works by contemporary American writers who depict characters' search of their psychological and cultural identity. Among those contemporary writers is Cormac McCarthy (1933-) whose "All the Pretty Horses" (1992) tackles this quest for identity as its basic theme, both psychologically and culturally. This paper is an attempt to investigate both dimensions of the quest in this novel as being one of McCarthy's masterpieces.