Since the early 1980s, epidemiological studies using state-of-the-art methodologies have documented the unmet mental health needs of Latinos adults in the U.S. and Puerto Rico. This paper reviews 16 articles based on seven epidemiological studies, examines studies methodologies, and summarizes findings about how Latino adults access mental health services. Studies consistently report that, compared to non-Latino Whites, Latinos underutilize mental health services, are less likely to receive guideline congruent care, and rely more often on primary care for services. Structural, economic, psychiatric, and cultural factors influence Latinos' service access. In spite of the valuable information these studies provide, methodological limitations (e.g., reliance on cross-sectional designs, scarcity of mixed Latino group samples) constrict knowledge about Latinos access to mental health services. Areas for future research and development needed to improve Latinos' access and quality of mental health care are discussed.