Background <p>Care analyses show that evidence-based measures such as compression therapy and promotion of mobility are rarely implemented in treatment of Venous leg ulcers. The Ulcus Cruris Care project developed a disease- management approach to support evidence-based venous leg ulcer treatment in general practices. This included online training and three e-learning modules for practice teams, software-supported case management, involvement of non-physician assistants, and promotion of patient activation and education. The intervention program was implemented within a multicenter randomized controlled trial (Ulcus Cruris Care). A mixed-methods process evaluation explored intervention fidelity and perceived effects to identify improvement potential.</p> Methods <p>The cross-sectional process evaluation design applied semi-structured guide-based qualitative telephone interviews and a study-specific survey to evaluate the implementation process of the program.</p> Results <p><i>N</i> = 38 survey questionnaires were completed and <i>n</i> = 27 interviews were conducted (<i>n</i> = 10 general practitioners, <i>n</i> = 10 non-physician assistants, <i>n</i> = 7 patients). Findings indicate high intervention fidelity regarding completion of the online training (100%), the e-learning modules (between 61% and 48%), application of standard operating procedures (100%), patient education material (91%), and case management software (91%). Practice teams and patients positively perceived the role of non-physician assistants as case managers and their involvement in wound treatment and patient education. Overall, the program was perceived as effective in promoting change in treatment routines, particularly the regular use of compression therapy as the most effective treatment measure, improving patient and practice team education, and ultimately, wound healing.</p> Discussion <p>The intervention program was expected to increase the use of compression therapy, speed up healing, and reduce the use of medical resources. Participants in this process evaluation perceived the program as supporting structured venous leg ulcer treatment, increasing relevant knowledge among practice teams and patients, and encouraging more active involvement of patients and relatives. The outcome analysis in the Ulcus Cruris Care trial strengthened these findings and suggested a potential benefit of the intervention.</p> Conclusion <p>Promotion of comprehensive VLU treatment and care in general practices, including a regular use of compression therapy and active patient participation as facilitated by this intervention program appears to be largely suitable for a venous leg ulcer case management approach.</p> Trial registration <p>The Ulcus Cruris Care trial protocol was registered in the German Clinical Trials Register on August 30, 2021 (DRKS00026126).</p>