Fibromyalgia syndrome (FMS), a common chronic pain condition, is often incompletely treated by conventional medical therapies. It can cause disability, psychological distress, work-related absenteeism, increased use of healthcare resources, and result in the inability to carry out the tasks of daily living. The purpose of this quantitative, correlational study was to investigate the potential influence of laughter on affect and pain in individuals with FMS. Laughter produces beneficial effects on acute pain and on chronic pain in general and has been found to improve temporary affective states, but there have been no studies testing the effects of laughter on the pain and affect of fibromyalgia patients. Informing this study were the gate control and neuromatrix theories of pain, as well as the dynamic model of affect theory. The research questions addressed whether laughter frequency is associated with affect and or with perceived chronic pain levels in these individuals. Forty-one adult fibromyalgia patients documented all laughter episodes daily and assessed their pain and affective states 3 times per day for 14 days. Hierarchical regressions revealed that increased overall laughter frequency was significantly associated with decreases in overall pain and increases in overall positive affect but was not associated with measures of negative affect. Also, morning laughter frequency was predictive of increased afternoon and evening positive affect ratings, as well as with decreased afternoon pain ratings, but was not significantly associated with evening pain ratings. The knowledge gained from these results may have positive social change implications at the individual level, within those individuals' larger social networks, and within the research and medical communities.