BACKGROUND AND OBJECTIVE Previous research suggests that measures of cognitive process may be confounded by the inclusion of items that also assess cognitive content. The primary aims of this content review were to: (1) identify the domains of cognitive processes assessed by measures used in pain research; and (2) determine if pain-specific cognitive process measures with adequate psychometric properties exist. DATABASES AND DATA TREATMENT PsychInfo, CINAHL, PsycArticles, MEDLINE, and Academic Search Complete databases were searched to identify the measures of cognitive process used in pain research. Identified measures were double coded and the measure's items were rated as: (1) cognitive content; (2) cognitive process; (3) behavioural/social; and/or (4) emotional coping/responses to pain. RESULTS A total of 319 scales were identified; of these, 29 were coded as providing an un-confounded assessment of cognitive process, and 12 were pain-specific. The cognitive process domains assessed in these measures are Absorption, Dissociation, Reappraisal, Distraction/Suppression, Acceptance, Rumination, Non-Judgment, and Enhancement. Pain-specific, un-confounded measures were identified for: Dissociation, Reappraisal, Distraction/Suppression, and Acceptance. Psychometric properties of all 319 scales are reported in supplementary material. CONCLUSIONS To understand the importance of cognitive processes in influencing pain outcomes as well as explaining the efficacy of pain treatments, valid and pain-specific cognitive process measures that are not confounded with non-process domains (e.g., cognitive content) are needed. The findings of this content review suggest that future research focused on developing cognitive process measures is critical in order to advance our understanding of the mechanisms that underlie effective pain treatment. SIGNIFICANCE Many cognitive process measures used in pain research contain a 'mix' of items that assess cognitive process, cognitive content, and behavioural/emotional responses. Databases searched: PsychInfo, CINAHL, PsycArticles, MEDLINE and Academic Search Complete. This review describes the domains assessed by measures assessing cognitive processes in pain research, as well as the strengths and limitations of these measures.