Due to intense competition of contemporary business life, companies need to achieve significant quality performance for survival. Considering this fact, this study aims to define the factors affecting the quality performance of manufacturing firms and their influence levels. To accomplish this aim, a thorough literature study was conducted to define the quality performance factors. A model was constructed with the yielded 12 factors. By using these, a survey was conducted in 200 large-scale manufacturing firms randomly selected from a list of 1000 most successful firms defined by the Istanbul Chamber of Commerce, Turkey. Data were collected and analyzed by Structural Equation Modeling (SEM) to determine the influence levels of the quality performance factors on the overall quality of the firms. Reliability, conformance of the product to the design specifications, and durability are found to be the three most highly influencing factors, respectively, whereas delivery lead-time of finished products/services to customers is found to be the least influencing factor. The results are expected to help managers in defining their priorities in their quest for quality.