© 2018 International Association for the Study of Pain Research suggests that people living with HIV experience levels of pain disproportionate to the general population. Pain is a stressor that can negatively impact health-related quality of life. As the number of people aging with HIV increases, we must understand the dynamics of pain experiences among people living with HIV and how to effectively harness evidence-based treatments and supportive resources to enhance adaptive coping. We used an experience sampling method (also called Ecological Momentary Assessment) to assess moment-to-moment experiences of pain and social support 3 times a day for 7 days in a sample of 109 men living with HIV. Participants also responded to questionnaires assessing attachment-related insecurity and social support. In hierarchical linear modeling analyses controlling for age, race, sexual orientation, and socioeconomic status, we found that experiences of social support were associated with lower subsequent pain within-persons. On the other hand, experiences of pain were not associated with later experiences of social support. Men with higher levels of attachment-related avoidance reported more pain on average. Attachment-related avoidance also moderated the association between moment-to-moment experiences of felt social support on pain. Results suggest that within-persons, experiences of daily social support reduce experiences of pain. Between-persons, attachment style may influence how individuals make use of social support in coping with experiences of pain. These findings imply a need to assess social well-being at the clinic level and also support tailored biopsychosocial approaches to pain management in HIV care settings.