Mental health services in the UK have been repeatedly criticised for being insensitive to patients' religious and cultural needs. Muslims form Britain's largest ethnic minority group – nearly 3% of the UK population – yet, their health beliefs and practices remain relatively unexplored. We examined Muslims’ beliefs about Jinn, black magic and the evil eye and whether believed affliction by these supernatural entities could cause physical or mental health problems and also whether doctors, religious leaders, or both should treat this. A self-report questionnaire was given to a convenience sample of Muslims aged 18 years and over (n=111). The majority of the sample believed in the existence of Jinn, black magic and the evil eye and approximately half of them stated that these could cause physical and mental health problems and that these problems should be treated by both doctors and religious figures. Our results highlight an important area that demands attention from providers of health care.