BACKGROUND – Accurate self-reporting of keratinocyte carcinoma (KC) informs clinical decision-making, but real-world performance in dermatology clinics is understudied.OBJECTIVE – To evaluate the sensitivity, specificity, and accuracy of patient-reported facial or scalp KC, basal cell carcinoma (BCC), and squamous cell carcinoma (SCC) during routine dermatology encounters.PATIENTS AND METHODS – In this multicenter cohort study, 338 adults with Fitzpatrick phototypes I–III and visible actinic damage were prospectively enrolled at 6 academic centers. Participants self-reported their history of KC, BCC, and SCC within the prior 2 years. Chart review served as the reference standard. Diagnostic accuracy metrics were calculated, including worst-case sensitivity analyses.RESULTS – Self-reported KC showed high accuracy (92.2%), sensitivity (93.8%), and specificity (91.2%). SCC sensitivity was lower (78.3%) despite high specificity (95.9%). In worst-case analyses, SCC sensitivity declined to 64.3%. Negative predictive values exceeded positive predictive values across all cancer types.CONCLUSION – Patient self-reporting of KC is generally reliable, particularly for excluding disease. However, SCC is more likely to be underreported, underscoring the need to verify cancer history in high-risk patients or those at risk for poor recall.