Cognitive maps are mental representations of space essential for guiding spatial behavior. To assess the properties of these cognitive maps, sketch mapping has been widely used as a research tool in spatial cognition research. This scoping review aims to provide a comprehensive overview of the methodologies and the cognitive processes concerning the externalization of cognitive maps through sketch mapping. Following the PRISMA-ScR checklist (Tricco et al. in Ann Intern Med 169(7):467-473, 2018, https://doi-org.bibliotheek.ehb.be/10.7326/M18-0850), a comprehensive search from five electronic databases was performed with predefined combinations of keywords. Twenty-four articles were selected and analyzed, covering a wide range of methods: traditional pen-and-paper sketching (n = 18 studies); combination of pen-and-paper and digital sketching (n = 1); exclusively digital sketching (n = 4); and digital VR sketching (n = 1). With regard to the formation of cognitive maps in environmental scale spaces, studies employed either direct experience or virtual experience of unfamiliar environments, videos, maps, or retrieval from own memory. This review highlights the inherent conflict between sketch maps' advantages in capturing knowledge in less structured experimental protocols and researchers' need for structured quantification of their quality, as well as the underused diversity of media through which sketch maps can be produced for appropriate scenarios. We encourage researchers to (a) increase the precision in reporting the cognitive processes being investigated with sketch maps (e.g., short-term vs. long-term memory), (b) rely on established data analysis methods instead of developing custom measures for each study, and (c) consider alternative media beyond pen and paper when more suitable to the experimental context.