There is a current problem that companies have when they do not know if their position declared through green marketing is effective or not, since there are no studies that prove its real impact on the young population, specifically on university students in Lima, so the research question is: how green marketing affects the purchasing decisions of university students in Lima, 2019? Before that, it is proposed as a hypothesis: green marketing positively affects the purchasing decisions of university students in Lima, 2019. The study is of an applied and explanatory type, with a non-experimental cross-sectional design. We obtained data from a sample of 622 university students from Lima, Peru, which when treated through the Pearson Chi-Square test allows us to validate the hypotheses raised.