Underutilization of mental health services is a function of the difference between actual prevalence of psychological dysfunction and need, and the number of treated cases. An extensive evaluation was conducted of the empirical literature on the underutilization of mental health services by lower socioeconomic status Mexican-Americans. The literature reviewed defined and provided evidence of Mexican-American underutilization of traditional mental health services. Significant barriers that hinder utilization were identified. They included Mexican cultural tradition, acculturation, the Mexican-American view of psychopathology and healing, socioeconomic status, level of psychopathology, the therapeutic relationship, and expectations regarding mental health services. It was also revealed that mental health agencies have attempted to enhance utilization by developing more professional sensitivity to the issues of acculturation and language differences. Research revealed that Mexican-Americans responded better to more problem-oriented treatment. Orientation programs, which provide both the Mexican-American client and the Anglo-American therapist with ways to better understand each other have also proved beneficial. (Sixty-five references are included.) (Author/NB)