Background: Exercise is nowadays considered as an evidence-based treatment modality in people with mental illness. Nurses and occupational therapists working in low-resourced mental health settings are well-placed to provide exercise advice for people with mental illness. Objectives: We examined the current exercise prescription practices employed by Ugandan health care professionals when working with people with mental illness, and identified perceived barriers to exercise prescription and exercise participation for people with mental illness. Methods: In this study, 31 Ugandan health care professionals 20 men; 31.2 ± 7.1 years completed the Exercise in Mental Illness Questionnaire– Health Professionals Version EMIQ-HP. Results: The vast majority of the respondents 29/31, 94% reported they prescribed exercise at least “occasionally” to people with mental illness. Exercise-prescription parameters used were consistent with those recommended for people with mental illness. Regarding barriers to exercise participation, coping with side effects of psychotropic medication at the individual level and reducing stigma at community level should be prioritized. Conclusion: A health care reform to enable collaboration with exercise professionals, such as exercise physiologists or physiotherapists, might increase exercise uptake for people with mental illness, thereby improving health outcomes for this vulnerable population.