In Ghana, people with mental disorders commonly experience negative attitudes and discrimination because of deep-rooted public stigma. The aim of the study was to assess the effectiveness of a mental health literacy programme in improving community leaders’ attitudes toward people with mental disorders. A cluster randomised controlled trial, comprising an intervention and control group, participated in a 3-hour problem-solving, Story-bridge mental health literacy programme. Data were collected at baseline and 12-week follow-up. The intervention group performed better in most outcome measures at follow-up compared to the control group. There were statistically significant differences between the two groups, in perceived stigma, community mental health ideology (CMHI), and benevolence outcome measures over the two time-points. Overall, the findings suggest that the programme was somewhat effective in improving community leaders’ attitudes and who might, subsequently, foster supportive, non-judgemental and empathetic attitudes toward individuals with mental disorders in their communities. There is scope for community psychiatric nurses and other primary health care workers to work with community leaders to increase public awareness of, and favourable attitudes toward, people with mental health problems in the community.