Peace scholars, practitioners, and policymakers increasingly recognize the pitfalls of focusing primarily on peace programming and related technical skills to achieve sustainable peace goals in constantly evolving conflict and post-conflict situations. Three broad reasons explain this recognition: First, studies show that insensitive attitudes, social biases, and ambivalence among peace professionals significantly increase fragility, conflict, and violence (Autesserre, 2014; Lederach, 2016) thereby jeopardizing development initiatives. Second, there is no straightforward path to becoming a peace professional, which contributes to less coordinated/integrated peace and development goals (Kastner, 2021; Scholten, 2020). Finally, the conduct and integrity of peace professionals is increasingly called into question (e.g., the reports of sexual misconduct by UN personnel in DRC). While these observations increase our awareness of the need and urgency to improve peace practice, there is no professionally shared approach to peace professionalism to increase the effectiveness and sustainability of peace efforts. This workshop focuses on the interrelationship between peace, conflict, and development in uncertain conflict and development contexts. Drawing on the sociology of professions (Evetts, 2006), theories of practice (Bourdieu, 1990), and participatory research methods, it addresses two interrelated questions: a) How do peace professionals know whether they possess the skills, competencies, and values necessary to be effective in their work? and b) What makes one an effective peace worker, particularly in uncertain conflict and development contexts? Overall, this workshop seeks to generate scholarly and policy debates around peace professionalism as a body of knowledge that informs both the process and approach to peace practice in uncertain conflict and development contexts. Workshop participants will reflect on some of the core values, competencies, and skills required to be an effective peace practitioner.