The health emergency caused by the COVID-19 pandemic has transformed and decisively affected the entire education system, which has resulted in an urgent need to adapt it to an online scenario. Science education is an area that has been highly affected by and, as a consequence, science teachers were forced to make an extra effort to create virtual learning environments accessible for all students. This study offers a systematic review to synthesize how the COVID-19 pandemic has influenced science teachers' educational practices and adaptations. To this end, "Web of Science," ERIC and Scopus databases used to explore the virtual educational practices, e.g., teaching-learning processes, during the pandemic. The purpose of this study is to analyze the main bibliographic characteristics of the collected literature (research purpose, methodological design, geographical and temporal distribution, central themes) via thematic analysis. The findings offered a synthesis of studies that explain innovative practices, tools, and strategies that were very useful for teachers and students in the STEM area. We believe that future lines of research should be oriented towards broadening the analysis of different pedagogical approaches developed in the teaching of STEM areas during the health crisis by COVID-19. This could be useful for guiding professional and educational actions.