INTRODUCTION: Cognitive impairment is common in first-episode psychosis patients and often associated with poor quality of life and functional impairment. However, most literature on this association is from high income countries and not low resource countries like Uganda. We aimed to determine the association between cognitive impairment with quality of life and functional impairment in Ugandan first-episode psychosis patients. METHODS: At Butabika national psychiatric hospital of Uganda, we enrolled 94 first-episode psychosis patients aged 18-60 years with a confirmed first-episode of psychosis and no previous treatment with antipsychotic medication. Neuropsychological assessment was performed using the MATRICS consensus cognitive battery (MCCB). Quality of life and functional impairment were assessed using the brief version of the World Health Organisation Quality of Life scale (WHOQOL-BREF) and the MINI International Neuropsychiatric Inventory (MINI) respectively. Linear regression analyses determined the association between impairment in different cognitive domains with various quality of life and functional impairment domains while controlling for age, gender and level of education. RESULTS: High scores in the reasoning and problem solving cognitive domain were associated with better quality of life in the psychological domain of WHOQOL-BREF (p = 0.029). For functional impairment, high cognitive scores in the domains of speed of processing (p = 0.018), reasoning and problem solving (p = 0.015), working memory (p = 0.017) and visual learning and memory (p = 0.002) were associated with psychosis "having a greater impact on other members of the family" on the MINI. Higher scores in the social cognition domain were associated with "less aggressive and disruptive behaviour" (p = 0.003). CONCLUSION: Cognitive impairment in Ugandan first-episode psychotic patients is associated with both poorer quality of life and functional impairment. Remediation of cognitive function may be a plausible intervention to improve outcomes in Ugandan first-episode psychosis patients.