Cumulative lifetime adversity and social support were investigated as determinants of psychosocial adjustment (esteem, distress, hopefulness, positive outlook/future aspirations, and sense of purpose) over 12 months in 6-10-years-old HIV-infected, HIV-exposed uninfected and HIV-unexposed uninfected children from Uganda. Each determinant and psychosocial adjustment indicator was self-reported using standardized questionnaires administered at baseline, 6, and 12 months. Linear mixed effects models were used to relate time-varying lifetime adversity and social support to psychosocial adjustment over 12 months. Regardless of HIV status, higher adversity predicted lower esteem (coefficient b = -2.98, 95% confidence interval (CI): [-4.62, -1.35]) and increased distress (b =3.96, 95% CI: [1.29, 6.62]) but was not associated with hopefulness, positive outlook or sense of purpose. Low social support predicted higher distress (b =9.05, 95% CI: [7.36, 10.73]), lower positive outlook (b = -10.56, 95% CI: [-2.34, -8.79]) and low sense of purpose (b = -9.90, 95% CI: [-11.44, -8.36]) over 12 months. Pragmatic interventions that enhance coping with adversity and provide emotional/instrumental support should be tested for effectiveness in promoting resilient psychosocial adjustment trajectory in vulnerable children.