Copyright © 2016 John Wiley & Sons, Ltd. Objective: Internationally, the Distress Thermometer and associated Problem List are increasingly used in oncology as screening tools for psychological distress. Cancer-related fatigue is common but often overlooked in clinical practice. We examined if severe fatigue in cancer patients can be identified with the fatigue item of the Problem List. Methods: Newly diagnosed breast (N = 334) and colorectal (N = 179) cancer patients were screened for severe fatigue, which was defined as having a positive score on the fatigue item of the Problem List. The Fatigue Severity subscale of the Checklist Individual Strength was used as gold standard measure for severe fatigue. Results: In total, 78% of breast cancer patients and 81% of colorectal cancer patients were correctly identified with the fatigue item. The sensitivity was 89% in breast cancer patients and 91% in colorectal cancer patients. The specificity was 75% in breast cancer patients and 77% in colorectal cancer patients. The positive predictive value was 53% in breast cancer patients and 64% in colorectal cancer patients, whereas the negative predictive value was 95% in both tumor types. Conclusions: The fatigue item of the Problem List performs satisfactorily as a quick screening tool for severe fatigue. However, a positive screen should be followed up with a more thorough assessment of fatigue, ie, a questionnaire with a validated cutoff point. Given time pressure of clinicians, this already implemented and brief screening tool may prevent severe fatigue from going undetected in clinical practice.