The purpose of this study was to examine patterns and predictors of HIV/STI risk over time among Latino migrant men in a new receiving community. Latino men (N = 125) were interviewed quarterly for 18 months and HIV/STI tested annually. Selected individual, environmental and cultural factors by partner type and condom use were explored longitudinally and in a cross-section. Sex with female sex workers (FSWs) and multiple partners decreased, sex with main partners and abstinence increased, while the number of casual partners remained stable. Consistent condom use was highest with FSWs, lowest with main partners and midrange with casual partners with no trends over time. STI morbidity was low; no HIV was detected. Drug use and high mobility were associated with inconsistent condom use with FSW, whereas having family in the household was protective. HIV/STI prevention efforts should focus on drug using Latino migrants who are highly mobile and should foster healthy social connections.