PURPOSE: Informing adolescents of their own HIV infection is critical as the number of adolescents living with HIV increases. We assessed the association between HIV disclosure and retention in care and mortality among adolescents aged 10-14 years in Kenya's national program. METHODS: We abstracted routinely collected patient-level data for adolescents enrolled into HIV care in 50 health facilities from November 1, 2004, through March 31, 2010. We defined disclosure as any documentation that the adolescent had been fully or partially made aware of his or her HIV status. We compared weighted proportions for categorical variables using χ2 and weighted logistic regression to identify predictors of HIV disclosure; we estimated the probability of LTFU using Kaplan-Meier methods and dying using Cox regression-based test for equality of survival curves. RESULTS: Of the 710 adolescents aged 10-14 years analyzed; 51.3% had severe immunosuppression, 60.3% were in WHO stage 3 or 4, and 36.6% were aware of their HIV status. Adolescents with HIV-infected parents, histories of opportunistic infections (OIs), and enrolled in support groups were more likely to be disclosed to. At 36 months, disclosure was associated with lower mortality [1.5% (95% CI .6%-4.1%) versus 5.4% (95% CI 3.6.6%-8.0%, p < .001)] and lower LTFU [6.2% (95% CI 3.0%-12.6%) versus 33.9% (95% CI 27.3%-41.1%) p < .001]. CONCLUSIONS: Only one third of HIV-infected Kenyan adolescents in treatment programs had been told they were infected, and knowing their HIV status was associated with reduced LTFU and mortality. The disclosure process should be systematically encouraged and organized for HIV-infected adolescents.