Background: Previous research has found that acceptance of pain is more successful than cognitive coping variables for predicting adjustment to pain. This research has a limitation because measures of cognitive coping rely on observations and reports of thoughts or attempts to change thoughts rather than on overt behaviours. The purpose of the present study, therefore, is to compare the influence of acceptance measures and the influence of different behavioural coping strategies on the adjustment to chronic pain. Methods. A sample of 167 individuals diagnosed with fibromyalgia syndrome completed the Chronic Pain Coping Inventory (CPCI) and the Chronic Pain Acceptance Questionnaire (CPAQ). Results: Correlational analyses indicated that the acceptance variables were more related to distress and functioning than were behavioural coping variables. The average magnitudes of the coefficients for activity engagement and pain willingness (both subscales of pain acceptance) across the measures of distress and functioning were r = 0.42 and 0.25, respectively, meanwhile the average magnitude of the correlation between coping and functioning was r = 0.17. Regression analyses examined the independent, relative contributions of coping and acceptance to adjustment indicators and demonstrated that acceptance accounted for more variance than did coping variables. The variance contributed by acceptance scores ranged from 4.0 to 40%. The variance contributed by the coping variables ranged from 0 to 9%. Conclusions: This study extends the findings of previous work in enhancing the adoption of acceptance-based interventions for maintaining accurate functioning in fibromyalgia patients.