While epidemiological description of psychiatric morbidity can promote evidenceinformed mental health services, there is a paucity of such evidence among incarcerated individuals in prisons with underserved healthcare. We evaluated 250 incarcerated individuals detained in an underserved prison in north-western Nigeria with the Mini International Neuropsychiatric Inventory (MINI). Predominantly, study participants were men (97.6%) and the mean age was 35.4 (SD=13.5) years. The majority of the incarcerated individuals (81.2%) were awaiting trial, the most common crime was armed robbery (38.8%), and 16.4% of participants were recidivists. The prevalence of psychiatric morbidity was 47.4%, with major depression being the most common diagnosis (23.2%). The majority (92.8%) had no prior contact with psychiatric treatment. Being single, employed, and lacking prior psychiatric treatment were independently associated with psychiatric morbidity (R2=0.27). These findings underscore the need for better investment in correctional mental health services. Multi-pronged efforts with multisectoral collaboration between the government and other stakeholders to develop scalable interventions are advocated.