Chronic mental illnesses have long periods, are recurring, and require continuous care as well as an integrated and collaborative approach to organize the care. The purpose of this article is to summarize the most important steps necessary for adapting a clinical practice guideline for family-centered collaborative care of patients with chronic mental illnesses referring to the medical centers. As the study will be an exploratory mixed methods study, the design will be carried out as a sequential qualitative-quantitative study (QUAL quan), consisting of 3 phases, 9 modules, and 24 sequential steps, which is based on the Guidelines International Network to adapt the guideline manual. In the first phase, the prerequisites for adaptation of the clinical guideline were established. In the second phase, to collect evidence, a qualitative study (semi-structured interview) will be conducted to explore the dimensions and components of the care needs of patients with chronic mental disorders and their families from the perspectives of patients, caregivers, and healthcare providers. Additionally, a literature review to extract relevant clinical guidelines and articles will be done. A panel of experts will screen and evaluate potential clinical guidelines, and a draft guideline will be developed. It is expected that these findings will meet the needs of patients with mental illness and their caregivers by providing integrated care and improving collaborative care within the sociocultural context of Iran.