How to increase student engagement in the classroom and prepare the students for the future are questions that teachers have been pondering for decades. Over the years, many different student-centered teaching methods have been introduced to varying degrees of success. This literature review investigates one of the student-centered teaching methods that has been shown to have positive benefits for students in secondary classrooms, project-based learning (PBL). In a PBL unit or lesson, the students are investigating a real-world question or problem and then presenting their learning in a final project. Through the creation of the final product, the students will be gaining a deeper understanding of the learning, as well as, developing critical 21st century skills. Even though the ideas for PBL was initially theorized in the early 20th century, it has shown capable of helping students be successful today.