The paper is focused on the analysis of nonconforming products and improving their quality, which represents a significant benefit for the company. The analysis is focused on a selected type of products that were produced over a period of four years. The occurrence of nonconforming products was determined based on customer complaints. The basic quality management tools were used in the analysis. Based on the findings of the main causes of nonconforming products, corrective measures were proposed and the benefits from the implemented measures were evaluated