In low-income countries, clinicians must seek strategies to improve treatment adherence that are non-resource intensive and easily integrated into existing treatment structures. We conducted a prospective observational cohort study to investigate the relationship of family engagement in treatment during hospitalisation with post-discharge appointment and medication adherence in 81 patients from a Nigerian psychiatric hospital. After controlling for gender, diagnosis, mental state at discharge, and marital status, family involvement was significantly associated with appointment (P=0.047) but not medication adherence (P=0.590). Studies are needed to determine whether interventions based on engaging families in treatment can improve post-discharge adherence in this setting.