This research explores if quality management practices are different among suppliers whose performance is rated high, medium, or low by a common buying company and identifies which specific practices contribute to the differences. The entire population of first-tier supplier to a Korean outo assembler was surveyed to measure use of quality management practices. Useable returns were received from 25% of the suppliers serveyed. To measure conformance quality and overall rating, analysis of variance was done using general liner model (GLM_MANOVA) to explore differences in the high-, medium-, and low-performing supplier groups based on their use of quality mangement practices. No statistically significant differences were found when suppliers were categorized based on conformance quality. However, when categorized based on overall rating, the highest rated suppliers were found to emphasize process management and employee stisfaction to a greater degree than the lowest rated suppliers.