In experimental research must have external and internal validity in order to control secondary variables. External validity relates to the generalization of research results, while internal validity relates to the extent of the causal relationship between the independent variable and the dependent variable. Therefore, it is important to examine internal and external validity in experimental design. The method used in this study is a systematic literature review. The database used for literature search utilizes two digital libraries, namely Google Scholar and Scopus. The literature search will take place in May 2024. In order for the selected literature to be relevant, the search uses the keyword "internal external validity". The analysis technique used is a narrative method by grouping the data being explored. This research is expected to provide information related to internal and external validity in experimental design