This study aimed at examining the quality management practices of building contractors in Nakuru town and how these practices influence successful completion of projects. The study utilized the descriptive survey design where a sample of 107 building contractors was selected from the target population of 335 National Construction Authority registered building contractors in Nakuru town using the proportionate stratified sampling method. Data was collected from the selected companies using structured questionnaires, and analyzed using both descriptive and the multiple linear regression technique. Results revealed that all the four components of quality management have a statistically significant and positive relationship with successful completion of building construction projects in Nakuru town. The study recommended that building construction firm invest in quality management especially quality improvement in order to increase their rate of project completion success. Policy makers should also introduce quality management courses in the training curricular of key construction workers such as engineers and project managers so as to improve the implementation of construction projects.