Background Physical inactivity has contributed to the current prevalence of many age-related diseases, including type 2 diabetes and cardiovascular disease. Peer coach physical activity intervention are effective in increasing long term physical activity in community dwelling older adults. Linking peer coach physical activity interventions to formal care could therefore be a promising novel method to improve health in inactive older adults to a successful long-term physical activity intervention. Methods We evaluated the effects of linking a peer coach physical activity intervention in Leiden, The Netherlands to primary care through an exercise referral scheme from July 2018 to April 2020. Primary care practices in the neighborhoods of three existing peer coach physical activity groups were invited to refer patients to the exercise groups. Referrals were registered at the primary care practice and participation in the peer coach groups was registered by the peer coaches of the exercise groups. Results During the study, a total of 106 patients were referred to the peer coach groups. 5.7% of patients participated at the peer coach groups and 66.7% remained participating during the 1 year follow up. The number needed to refer for 1 long term participant was 26.5. The mean frequency of participation of the referred participants was 1.2 times a week. Conclusion Linking a peer coach physical activity intervention for older adults to a primary care referral scheme reached only a small fraction of the estimated target population. However, of the people that came to the peer coach intervention a large portion continued to participate during the entire study period. The number needed to refer to engage one older person in long term physical activity was similar to other referral schemes for lifestyle interventions. The potential benefits could be regarded proportional to the small effort needed to refer.