The study compared outcomes of uptake, attendance, and completion between two patient groups (mental health, n = 134 and physical health, n = 2767) in a physical activity referral scheme in the UK during 2000 to 2003. Despite similar rates for the physical health and mental health groups for initial progression (94% vs. 90%), referral uptake (60% vs. 69%; p < 0.001) and programme completion (22% vs. 34%; p < 0.001) were significantly lower in the mental health referrals. In conclusion, physical activity referral schemes appear to be less well suited to the needs of the mental health patient. Further research is recommended.