One of the main causes of defaults and disputes in the public construction projects of Saudi Arabia is attributed to the lack of adequate contractor prequalification and selection. Typically, contractor selection decisions are based merely on price,with absence of better selection criteria. The focus of this paper, therefore, is to identify essential criteria for contractor prequalification and selection processes at semi-government organizations in Saudi Arabia, under the design-bid-build approach for competitive tenders. At first, initial criteria were identified from the literature. Afterwards, three rounds of Delphi process were used to revise the initial criteria and to establish a consensus towards their acceptance. As a result, two sets of criteria were identified: 29 for prequalification and 40 for contractor selection. After the second and third round surveys, all levels of criteria were accepted except for some criteria with low level of importance. Once all the criteria were identified, their weights were determined based on consultation with expert professionals. The identified criteria and weights represent important steps towards improving the competitive tendering practices in Saudi Arabia and can be directly used to properly select contractors to avoid construction performance problems.