“What matters most” (WMM) is a theoretical framework based on medical anthropology and draws on cultural concepts of values and morals. It has been employed to identify cross-cultural aspects of mental health stigma. This approach assists practitioners, advocates, and researchers in assessing stigma-related factors that are relevant to the experiences of individuals in diverse cultural contexts. To implement effective anti-stigma programmes it is vital to identify and prioritize WMM for primary healthcare providers and people with lived experience of mental health conditions (PWLE). Our current objective was to explore WMM to primary healthcare providers, PWLE, primary care managers, and policymakers in Lebanon to inform mental health stigma reduction initiatives.