Amid challenges in mathematics education, students' low problem-solving skills have become a key concern. Studies have shown that many students struggle to understand problems, devise appropriate strategies, and validate their solutions, especially when faced with real-world mathematical tasks. Problem-Based Learning (PBL) has been identified in many studies as a promising approach to address this issue. This study aims to evaluate the effectiveness of PBL in enhancing students' mathematical problem-solving skills through a systematic review of recent literature. Using the PRISMA (Preferred Reporting Items for Systematic Review and Meta-Analysis) method, this Systematic Literature Review (SLR) identified 20 relevant articles from 1,672 collected through databases like ERIC, ScienceDirect, IOP Science, and PubMed, using keywords "Problem-based Learning" and "problem-solving mathematics." The findings show that PBL consistently improves students' problem-solving skills and is more effective than traditional teaching methods. Thus, PBL is a valuable instructional model for educators to adopt. This review suggests that PBL should be integrated more systematically into mathematics instruction to support students in developing essential 21st-century skills.