He is primarily interested in the ethnographic study of sexuality and HIV prevention in Mexico and with Latino populations in the U.S. His current research analyzes how the sexuality of Mexican gay immigrants influences their paths of migration to the U.S., their incorporation into U.S. life, and their sexual health and HIV risk. He is also conducting a study about the effects of acculturation on HIV risk among heterosexual Mexican Americans and Mexican immigrants. Dr. Carrillo was previously co-investigator in a study of drug use and unprotected sex among Latino gay men, and conducted an ethnographic study of sexuality and HIV prevention in Guadalajara, Mexico. The results of this latter study were published in book format as The Night Is Young: Sexuality in Mexico in the Time of AIDS (University of Chicago Press, 2002).