Abstract: The study aimed at examining family functioning and mental wellbeing of married couples in Ongata Rongai Ward, Kajiado County, Kenya. The specific objectives of the study were to: assess the relationship between family communication patterns and mental well-being of the couples, establish the influence of family problem-solving techniques on the mental well-being of the couples, investigate the relationship between family behavior control and mental well-being of the couples, and determine the influence of family affection on the mental well-being of the couples in Ongata Rongai Ward, Kajiado. The study was guided by the Bowen’s System Family theory.