Objective: Timely screening and intervention can prevent the development of the diabetic foot. However, delayed visits to the clinic are common among diabetic foot patients. The study aimed to develop and validate a questionnaire to assess healthcare-seeking behavior among patients with diabetic high-risk foot. Methods: The questionnaire of healthcare-seeking intention for patients with diabetic high-risk foot was developed in two phases: (1) Developing the questionnaire: 1) questionnaire items were formulated after literature review, group discussion and semi-qualitative interview; 2) a two-round modified Delphi method was to examine the content validity and the degree of consistency in questionnaire items; 3) conducting pre-survey to revise the questionnaire items. (2) Assessing the internal reliability and construct validity. Results: The final questionnaire consisted of five main themes and 28 items with a five-point rating. Cronbach's alpha coefficients for the five dimensions were respectively 0.937 (relevant knowledge of diabetic foot), 0.669 (attitudes toward seeking care), 0.896 (social support for seeking care), 0.621 (efficacy in coping with foot symptoms), 0.871 (intention to seek care). The Scale-level Content Validity Index of the five parts was 1.00, 0.80, 1.00, 1.00, and 1.00, respectively. The Kaiser-Meyer-Olkin values for each dimension was greater than 0.7, and the p-value for Bartlett's test of sphericity was less than 0.05. Conclusion: This questionnaire showed good validity, internal consistency, and reliability. It provided a potentially useful instrument to evaluate healthcare-seeking intention among patients with diabetic high-risk foot.