Rumination predicts wellbeing and is a core construct in the cognitive vulnerabilities to depression literature. Traditional measures of depressive rumination (e.g., Ruminative Responses Subscale, RRS; Treynor et al., 2003) rarely include items capturing thoughts about problems or events, even though these thoughts are in measures of related constructs (e.g., co-rumination, post-event processing). We created the Rumination on Problems Questionnaire (RPQ) for use on its own and with the RRS to capture rumination about problems and to align with measures of other ruminative and repetitive thinking processes. Our cross-sectional study of 927 undergraduates revealed the RPQ had a single factor, good internal reliability, convergent and discriminant validity, and significantly predicted depression, anxiety, and stress controlling for the RRS and co-rumination. Researchers and clinicians interested in rumination or cognitive vulnerabilities may wish to include the RPQ in their assessments. Measuring and addressing problem-focused rumination may be an important transdiagnostic treatment and prevention goal.