Purpose: This paper aims to explore informal learning experiences among employees working in South Korean small- and medium-sized enterprises (SMEs) with fewer than 100 employees. This study specifically seeks to understand the characteristics of informal learning in Korean SMEs and culturally sensitive contextual factors that shape informal learning. Design/methodology/approach: To understand the complex, holistic nature of the phenomenon, the current study used a phenomenological qualitative approach. Eighteen full-time employees working at South Korean SMEs in knowledge-intensive industries were interviewed. Data were analyzed using Moustakas's phenomenological analysis. Findings: The findings emerged from the field data revealed four characteristics of informal learning in South Korean SMEs: absolute reliance on informal learning; rapid/immediate learning and application; relationship/client needs-based learning; and extensive trial and error. The current study also identified South Korean SMEs' unique organizational context (i.e. a family-like atmosphere, one employee-multiple tasks, passive investment in employees and the absence of systems) and Korean culture (i.e. Gab-Eul relations and chemyon) that drive the emergence of SMEs' informal learning characteristics. Originality/value: Very little empirical research has been conducted to explain how informal learning actually occurs and why such learning patterns have emerged in South Korean SMEs. The findings of this study have a profound impact on practice and academia, as it unveils characteristics of informal learning in SMEs, the unique cultural context in which Korean SMEs operate and how these characteristics impact the learning process.