This study investigated whether higher maternal psychological distress, lower provision of psychosocial stimulation and a negative appraisal of parenting experience were associated with lower cognitive, motor, social-emotional and adaptive behaviour development in children under 3 years of age in Kenya. A cross-sectional design was used, with 81 caregiver-child dyads recruited through convenience sampling. The mean age of these infants was 8.5 months (SD = 5.6 months, range 23 days to 25.5 months). Higher maternal psychological distress was associated with lower social-emotional development, but not cognitive, motor and adaptive development of a child. Psychosocial stimulation provided by mothers was not related to any developmental outcomes. Maternal psychological distress and appraisal of parenting experience were significant, unique predictors of child social-emotional development. Findings suggest that interventions designed to promote social-emotional development of young children in Kenya should target maternal mental health and enhance confidence and experience of parenting.