Objective: The aim of this study was to gain better insight into the quality of patient participation in the development of clinical practice guidelines and to contribute to approaches for the monitoring and evaluation of such initiatives. In addition, we explore the potential of a dialogue-based approach for reconciliation of preferences of patients and professionals in the guideline development processes. Methods: The development of the Multidisciplinary Guideline for Employment and Severe Mental Illness in the Netherlands served as a case study. Methods for patient involvement in guideline development included the following: four patient representatives in the development group and advisory committee, two focus group discussions with patients, a dialogue session and eight case studies. To evaluate the quality of patient involvement, we developed a monitoring and evaluation framework including both process and outcome criteria. Data collection included observations, document analysis and semi-structured interviews (n = 26). Results: The quality of patient involvement was enhanced using different methods, reflection of patient input in the guideline text, a supportive attitude among professionals and attention to patient involvement throughout the process. The quality was lower with respect to representing the diversity of the target group, articulation of the patient perspective in the GDG, and clarity and transparency concerning methods of involvement. Conclusions: The monitoring and evaluation framework was useful in providing detailed insights into patient involvement in guideline development. Patient involvement was evaluated as being of good quality. The dialogue-based approach appears to be a promising method for obtaining integrated stakeholder input in a multidisciplinary setting.