Purpose <p>Grounded in Chinese healthcare and cultural background, this study aimed to develop and validate the Subjective Financial Distress Scale (SFDS) for cancer patients.</p> Methods <p>Between July and November 2022, cancer patients were recruited from the oncology department of a Grade A hospital in Jiangsu Province by the convenience sampling method. This research was conducted in three stages: Phase I (Item development) included domain identification and item generation based on a systematic literature review and preliminary qualitative interview results. Phase Ⅱ (Scale development) reduced items through Delphi expert consultation, a pilot test, item analysis and exploratory factor analysis. Phase III (Scale validation) evaluated the reliability and stability of the scale.</p> Results <p>A total of 452 patients were recruited. The final scale consisted of 24 items with 6 dimensions, including financial risk perception, changes in daily consumption patterns, changes in work status, changes in treatment plans, individual spontaneous emotional experiences and externally mediated interactive reactions. The scale’s Cronbach’s alpha, split-half reliability, test-retest reliability and content validity were 0.949, 0.902, 0.953 and 0.970, respectively. Comparison with the Comprehensive Scores for Financial Toxicity Based on the Patient-Reported Outcome Measures showed high calibration correlation validity (coefficient = 0.805). Confirmatory factor analysis showed that the first-order and second-order models both fit well, respectively.</p> Conclusion <p>The SFDS is reliable and valid to assess the degree of the subjective financial distress in cancer patients.</p>