In order to ensure quality work, the main contractor chooses suppliers based upon various quality attributes. The key to quality work on mega projects is to select best-quality suppliers. This research shows the data analysis results of preference rating of quality factors for supplier selection in Pakistan’s construction industry as per the importance accorded to each factor by the contractors. After thorough literature review and qualitative content analysis, a total of 25 factors were finalized and, then, a survey was conducted targeting well-known contractors in Pakistan. The weighted sum model (WSM) technique was used to analyze the overall preference of quality attributes through literature and respondent scores. Correlation analysis was also performed to select the most reliable weight split. After significant analysis, ten crucial attributes were identified for supplier selection in the construction quality domain. Quality management system certification, Product reliability and Capability of handling abnormal quality problems were the top three selection criteria.