Relations between grandmother and partner involvement (coresidence, social support, child care) and Puerto Rican adolescent mothers' parenting behaviors were examined. Few associations between grandmother involvement and behavior emerged, and these were moderated by coresidence. In contrast, partner involvement showed a number of significant (positive) direct and moderated relations with behavior. For both providers, the direction of the relations between social support and behavior during teaching was the opposite depending on coresidence: Greater social support was related to the display of more positive behavior among coresiding mothers but to less competent behavior among non-coresiding mothers. The relations between child care support and behavior differed across providers. For grandmothers, greater child care was related to less positive behavior during teaching among coresiding mothers but to more competent behavior among non-coresiding mothers. For partners, greater child care was more strongly related to positive behavior during play among non-coresiding than coresiding mothers. Results are discussed in light of Latino cultural values, developmental issues, and implications for intervention.