Small and medium-sized enterprises (SMEs) in the plastic commercialization sector are crucial for economic growth in Latin America, particularly in Peru. These SMEs often face challenges such as high return rates due to order fulfillment and product quality issues. Current literature lacks comprehensive solutions integrating Lean Warehouse methodologies tailored for this sector. This research aimed to bridge this gap by proposing a Lean Warehouse model incorporating Slotting, Visual Management, and Systematic Layout Planning (SLP) to address these challenges. The proposed model aimed to optimize storage, streamline workflow, and improve product quality, thereby reducing return rates and enhancing operational efficiency. Key results showed a reduction in the return rate from 17.65% to 12%, an increase in order fill rate from 83.45% to 97%, and improvements in delivery quality and on-time order ratios. This research significantly impacts both academic and socioeconomic spheres by providing a systematic approach to enhance SME performance in the plastic sector. Future research should explore further applications of Lean methodologies to sustain competitive advantage and foster innovation in SME operations.