Science, Technology, Engineering, and Mathematics (STEM) in Higher Education (HE) helps foster students’ motivation to continue studying and cultivates students’ regard for the role of science and technology in society. The gender gap in STEM HE can reduce through institutional efforts; however, the underrepresentation of women is prevalent. There have been efforts to research and implement strategies to increase the number of people attending STEM fields with a specific action to attract and retain women in these areas. Hence, the purpose of this research work is to carry out and show the results of a Systematic Mapping (SM) related to how HE institutions aim to address the gender gap in STEM education through research and educational innovation. The SM focused on published work from 2011 to 2021 indexed in Web of Science or Scopus. Findings show the state of knowledge for an essential topic: reducing the gender gap through guidance and retention strategies to attain completion. Furthermore, descriptive results give a general overview of the area, relevant trends, and other analytical evidence that provides an in-depth understanding of HE institutions’ needs. We conclude that the retention of women studying STEM HE has become an essential issue worldwide universities have addressed increasingly during the last decade.