The past 22 years of research on the underutilization of mental health services by Mexican Americans are critically analyzed from conceptual and technical perspectives. While basic assertions of previous investigators that underutilization exists are correct, research concepts and methods used have been inadequate in relation to the issue's complexity. An overemphasis on numerical equivalence of usage rates across ethnic groups as an evaluative measure ignores the critical impact of differences between groups on factors such as need, accessibility, and the service's compatibility with the client's needs. A conceptual restructuring of the issue of service utilization as an evaluative measure is suggested. Endeavoring to minimize the problems identified in past research, community mental health centers (CMHC) service use in Texas is examined, using the Texas Department of Mental Health and Mental Retardation records to obtain data by age, sex, ethnicity, and the major types of service used for the 28 CMHCs operational in 1978. While statistically significant numerical underutilization of services by Mexican Americans is not as widespread as past research might have claimed, substantial evidence exists that Mexican Americans continue to underutilize services in relation to their need, especially children and youth. The underutilization among Mexican American children and youth is explored in relation to their future mental health needs. (Author/NQA)