Clinical practice guidelines can improve the clinical and social care for marginalized populations, thereby improving health equity. The aim of this study is to identify determinants of guideline implementation from the perspective of patients and practitioner stakeholders for a homeless health guideline. We completed a mixed-method study to identify determinants of equitable implementation of homeless health guidelines, focusing on the Grading of Recommendations Assessment, Development and Evaluation Feasibility, Acceptability, Cost, and Equity Survey (GRADE-FACE) health equity implementation outcomes. The study included a survey and framework analysis. Eighty-eight stakeholders, including practitioners and 16 persons with lived experience of homelessness, participated in the study. Most participants favourably rated the drafted recommendations’ priority status, feasibility, acceptability, cost, equity impact, and intent-to-implement. Qualitative analysis uncovered stakeholder concerns and perceptions regarding “fragmented services”. Practitioners were reluctant to care for persons with lived experience of homelessness, suggesting that associated social stigma serves as a barrier for this population to access healthcare. Participants called for improved “training of practitioners” to increase knowledge of patient needs and preferences. We identified several knowledge translation strategies that may improve implementation of guidelines for marginalized populations. Such strategies should be considered by other guideline development groups who aim to improve health outcomes in the context of limited and fragmented resources, stigma, and need for advocacy.