Background: Within the project “Ulcus Cruris Care”, a disease management intervention to improve general practice care for patients with venous leg ulcer was developed, comprising online teaching for practice teams, standardized patient education, and case management. Implementation of the intervention was piloted and evaluated via a process evaluation. This study aims to evaluate contentedness with the intervention, implementation effort, implementation determinants, intervention fidelity, and perceived intervention effects using a mixed-methods process evaluation. Methods: The mixed-methods process evaluation explored the views of general practitioners, medical assistants and patients regarding the intervention components. Data were collected through semi-structured telephone interviews and a survey questionnaire. Qualitative data were first analyzed inductively, followed by a deductive–inductive approach based on the Theoretical Domains Framework. Survey data were analyzed descriptively. Results: Participants (n = 21) reported a strong contentedness with the intervention, high intervention fidelity, low implementation effort, and a change in perception of compression therapy as the central treatment element. Healthcare professionals emphasized increased patient education and patient and family involvement. Patients reported feeling better informed and empowered to take an active role in their treatment, primarily due to increased knowledge and skills in compression therapy. As a result, they were more content with their care and reported positive experiences with wound healing since trial participation. Conclusions: The Ulcus Cruris Care intervention can lead to a noticeable change in knowledge and potentially influence practice teams’ approach to venous leg ulcer management, facilitating a significantly more frequent use of compression therapy in VLU care. A confirmatory evaluation of potential effects in a definitive RCT seems warranted.