Given the potential for obesity to complicate migraine treatment outcomes, there is a need to understand patterns and correlates of acute medication use among individuals with this comorbidity. Experience sampling methodology (ESM) was used to characterize patterns of acute medication use among those with migraine and overweight/obesity and to examine individual and momentary factors related to medication use (both migraine-specific and nonspecific medications). Women with migraine and overweight/obesity (N = 170) seeking behavioral migraine treatment completed questionnaires followed by 28 days of daily ESM headache diaries. Participants used medications to treat 71.9% of attacks, 20% of which were treated with migraine-specific medications. Participants were more likely to use medication in the context of longer and more severe attacks that started earlier in the day. Presence of aura and greater work-related pain interference uniquely related to migraine-specific medication use. Questionnaire-assessed factors were not related to medication use, although older age and higher educational attainment related to more frequent use. A substantial proportion of attacks were left untreated, suggesting unmet treatment needs in this population. Results also suggest that ESM-assessed factors are more salient correlates of medication use compared to questionnaires. Additional investigation of barriers to medication use is needed.