Deploying open innovation initiatives is a risky and demanding venture for all types of organizations, but especially for public sector organizations (PSOs). This study identified 17 challenges, grouped in four categories, related to OI deployment: 1) Inter-organizational collaboration, 2) Innovation process, 3) Citizen engagement, and 4) Data and technology, as well as 18 good practices/organizational actions to increase the probability of success. Finally, two case studies, PULSAR and Cité de l'innovation et des savoirs Aix-Marseille (CISAM), were conducted to better understand how these practices can meet the challenges, while promoting value creation during the innovation cycle.