Latinos tend to be under-represented in cancer research and in bio-repositories. We conducted a Spanish-language, interviewer-administered cross-sectional survey of 331 foreign-born Latinos from Central and South America attending safety-net clinics in order to describe factors associated with knowledge about and intention to provide bio-specimens for research purposes. We used logistic regression and multiple imputation methods to evaluate associations between socio-cultural measures, medical trust, demographics, as well as knowledge about and intentions to provide bio-specimens. Almost half (47 %) of respondents knew what bio-specimens were, and 67 % said that they would provide a specimen after being given information about what this involved; this increased to 72 % among those with prior knowledge. Controlling for covariates, Latinos with a high school education and above were more likely to know what a bio-specimen was and to say they would provide bio-specimens than were those with lower levels of education [adjusted OR (aOR) 2.85, 95 % CI 1.37-5.96; and 3.49, 95 % CI 1.41-8.63, p ≤ 0.01, respectively]. Those with greater social integration were more likely to know about bio-specimens than those with less integration (aOR 2.54, 95 % CI 1.45-4.46, p = 0.001). Higher endorsement of family values was independently associated with intent to give bio-specimens (aOR 1.11, 95 % CI 1.02-1.20, p = 0.017 per five-point increase in "familism" score). Medical mistrust was not related to intentions to provide specimens. Our results suggest that interventions to increase willingness to provide bio-specimens could leverage trusted clinics or social networks and should consider individuals' education and socio-cultural perspectives.