In this study, we propose an innovative approach using the “Contextual Mobile Learning System” based on the “Electronic Performance Support System” (EPSS) to support efficient just-in-time learning for professionals working in the “Smart city”. In this paper, we present the principle and the structure of our contextual mobile learning system, which uses a search engine to find appropriate learning units in relation with working activities and conditions and the user’s / worker’s profile. We further discuss the proposed system structure, supportive process and context-driven engine. Finally, we describe a scenario using our contextual mobile learning system.