Introduction Treatment interruption (TI), defined as >28 days late for ART appointment, is one of the greatest challenges in controlling southern African HIV epidemics. Negative client-provider interactions remain a major reason for TI and barrier for return to care, especially for men. Motivational interviewing (MI) facilitates client-driven counseling and improves client-provider interactions by facilitating equitable, interactive counseling that helps clients understand and develop solutions for their unique needs. Fidelity of MI counseling in resource-constrained health systems is challenging. Methods We developed a male-specific MI curriculum for Malawian male TI clients. Four psychosocial counselors (PCs, a high-level Malawian counseling cadre) received a 2.5-day curriculum training and job-aid to guide MI counseling approaches. They participated in monthly phone-based discussions with their manager about MI-based solutions to challenges faced. PCs implemented the MI curriculum with men >15 years who were actively experiencing TI. Clients were found at home (through tracing) or at the facility (for those who returned to care on their own). MI counseling sessions were recorded, transcribed, translated into English, and coded in Atlas.ti v9. MI quality was assessed using a modified version of the validated Motivational Interviewing Treatment Integrity tool. The tool has two measures: 1) counts of key MI behaviors throughout the session (questions, reflections, etc.); and 2) overarching scores (using a five-point scale) that characterize three MI dimensions for an entire counseling session (cultivating change talk, partnership, and empathy). Results 44 MI sessions were recorded and analyzed between 4/1/22-8/1/22. 64% of counseling sessions focused on work and travel as the main reason for TI. 86% of sessions yielded client-driven, tailored solutions for overcoming TI. PCs implemented multiple MI behaviors very well: asking questions, giving information, simple reflections, and client affirmation. Few PCs used complex reflection, emphasized autonomy, or sought collaboration with clients. Among overarching MI dimensions, HCWs scored high in partnership (promoting client-driven discussions) and cultivating change talk (encouraging client-driven language and behavior change confidence) but scored sub-optimal in empathy. Only 5 sessions had confrontational/negative PC attitudes. Conclusions PCs implemented MI with fidelity and quality resulting in tailored, actionable plans for male re-engagement in HIV treatment in Malawi. Clinical Trial NumberNCT05137210andNCT04858243