To investigate whether the presence of parents constitute a protective factor against adverse reproductive health outcomes for adolescents living in slums of Nairobi, Kenya. The data come from a cross-sectional survey that canvassed a random sample of 4564 households representative of all Nairobi slums in February–June 2000. Structured questionnaires on household census, reproduction and adolescent health were verbally administered to household heads, women of reproductive ages, and adolescents, respectively. We restrict the analysis to a sub-sample of 788 never-married adolescent girls aged 12–19 years. We compare reproductive health outcomes of adolescents who live with neither parent, father only, mother only, and both parents. Data were analyzed using simple descriptive analysis and logistic regression models of three outcome variables: ever sexually active, ever experienced an unplanned pregnancy, and sexually active within the past 4 weeks. For each of the outcome variables, two models, one with and one without a proxy for adolescents' disorderly behavior are presented to establish whether parental presence affects adolescents' reproductive health. When the father is present in the household (i.e., father only or both parents present), adolescent girls are 42% less likely to have ever had sex ( p < .05), 45% less likely to have been sexually active in the most recent 4-week period ( p < 0.1), and 59% less likely to have ever experienced an unwanted pregnancy ( p < .05) than when neither parent, or only the mother, is present in the household. In the slums of Nairobi, father's presence, unlike that of the mother, is associated with stronger resilience among adolescents. When programming for adolescents in these resource-constrained settings, it is important, therefore, to involve parents.