Evidence suggests that among Hispanic/Latino populations in the United States, perceived discrimination is a significant stressor that may be a risk factor for unhealthy behaviors such as alcohol use, smoking and negative health outcomes such as depression. However, the Hispanic/Latino population might have different susceptibilities to the stressors of discrimination based on their specific heritage as they continue to be portrayed as a homogeneous group while disregarding the unique heritage-specific attributes that constitute this larger ethnic population. Aims : The aims of this dissertation were : (1) To examine whether self-reports of perceived discrimination across different Hispanic/Latino heritage groups were associated with alcohol use and abuse. (2) To determine whether reports of perceived discrimination across different Hispanic/Latino heritage groups were associated with smoking and (3) To assess the association between migration, discrimination and depressive symptoms among a population of indigenous Mayan migrants. Methods : In Chapters 2 and 3, 16,415 individuals who self-identified as Hispanic/Latino and were between the ages of 18-74 were randomly selected, recruited and interviewed by the Hispanic Community Health Study/Study of Latinos in the communities of The Bronx, New York; Chicago, Illinois; San Diego, California and Miami, Florida. Perceived discrimination and its association with alcohol use and smoking were explored. In Chapter 4, a total of 650 individuals of Tunkasen o heritage (a community of indigenous Maya from the Mexican state of Yucata n) were recruited binationally in the town of Tunka s and the satellite communities of Anaheim and Inglewood, California by The Mexican Migration Field Research Program staff. We assessed the association between migration history, religiosity and perceived discrimination. Results : Chapter 2 found that individuals of Cuban heritage who reported perceived discrimination were significantly more likely to report alcohol use. In Chapter 3 no significant association was found between those who reported perceived discrimination and smoking after controlling for identified psychosocial variables and alcohol use. Chapter 4 found that migration experience and current U.S. residence was associated with perceived discrimination, which in turn was associated with a higher risk for depressive symptoms, but this finding was not supported in gender-stratified analyses. Among women not living in the U.S, religiosity was associated with less discrimination. Also discrimination was found to be pervasive among male and female transnational and domestic migrants while religiosity served as a possible protective factor against discrimination for some women. Conclusions : Results from these studies have important implications for the development and restructuring of programs designed to assist Hispanics/Latinos with substance abuse or depression. Public health programs should include perceived discrimination and migration history as a potential risk for substance use and negative mental health outcomes, and be tailored individually to Hispanic/Latino heritage.