This study aims at examining the effect of using project-based learning on developing second-grade preparatory students' life skills in Social Studies. A sample of (60) female students from Jihan El-Sadat Preparatory School for Girls in Dakahlia governorate was divided equally into controlled and experimental groups. For data collection, a life skills situations test was developed and implemented. The results revealed that there is a statistically significant difference at the level (0.05) between the mean scores of the experimental group students who studied using the project-based learning strategy and the mean scores of the controlled group students who used the traditional method in the post-application of the life skills situations test which indicated the effectiveness of using project-based learning in developing life skills in geography for preparatory stage pupils. The study recommends training teachers on using and incorporating the project-based learning strategy, as well as using a set of teaching strategies that help learners acquire life.