This review synthesizes literature on computing pedagogical content knowledge (PCK). Shulman introduced PCK in the 1980s to describe the amalgam of knowledge teachers draw upon in their work and use of the construct is increasing in the computing education community. From a systematic search of the literature, I identified 19 articles drawn from 9 countries for review and summarize how computing PCK is conceptualized and investigated in the data set. Five conceptualizations of computing PCK were present: (a) two models of computing PCK components, (b) one model of PCK development and (c) two models focused on the metaphoric and problem-solving nature of computing. The most common research lines addressed were the nature and development of individual PCK. Mostly qualitative methods created by authors were employed. A focus on discipline-specific approaches for future computing PCK research is recommended.