Pedagogical content knowledge (PCK) refers to the content-specific knowledge that teachers use to promote students' learning of specific subject matter. PCK comprises multiple knowledge components that interact with each other when enacted in teachers' instructional practices. For many years, researchers lacked a robust methodological approach to unpack the structure and organisation of science teachers' PCK. In 2012, Park and Chen developed the PCK map approach to identify, quantify and visualise the complex interactions between PCK components that shape the instructional practices of science teachers. After a systematic literature search, we identified 22 studies from eleven geographical regions that used the PCK map approach to analyse the integration of science teachers' PCK components. An in-depth analysis of how the PCK map approach has been used, adapted and refined in these studies was performed. Findings reveal that some studies modified this approach in ways that did not retain the methodological strengths and robustness inherent in its original formulation. Some conflicting findings about the nature of the integration between PCK components are evident in the studies reviewed as well as in the broader literature on science teachers' knowledge. Issues related to the use of the PCK map approach and recommendations on how to use this approach to investigate science teachers' PCK are discussed.