Anal human papillomavirus (HPV) disproportionately affects men who have sex with men (MSM), particularly those who are older and those living with HIV. After experiencing difficulty recruiting older MSM into a study on aging and anal HPV, we conducted a sub-study to gain feedback on our recruitment methods and explore barriers and facilitators to participating in anal HPV research. We conducted focus groups with 30 men who have sex with men (MSM), both HIV-negative and MSM living with HIV, ages 50-75. We identified multiple themes that were barriers to participation including: (1) lack of knowledge about human papillomavirus and anal cancer; (2) research focused on anal cancer or discomfort with topics or procedures concerning the anus; (3) stigma including stigma associated with being men who have sex with men, being out, being a receptive partner, and being considered "older" in the gay community; and (4) confidentiality concerns including a fear of breach of confidentiality. Facilitators to participation were also identified; these motivational factors include altruism, wanting recommendations from a doctor, and desire to receive the best available care. Researchers seeking to enroll older men who have sex with men should be aware of these barriers and facilitators to participation in order to maximize recruitment.