Subcontractors handle a major portion - about 85% - of all construction projects in the building industry. The ability of the main contractor and consultants to deliver the project within time, quality and cost targets depends largely on the performance of the subcontractors. Selection of subcontractors on the basis of overall ability to perform is therefore crucial to successful project delivery. The key criteria for assessing subcontractors' eligibility for tender invitation and award, and subsequent performance at the construction stage, were investigated. Using the descriptive survey method, 243 contractors and 307 subcontractors registered with the Gauteng Master Builders Association of South Africa were surveyed. The multi-attribute technique was used to analyse the data. Results showed that quality record is the most influential criterion for selecting high performing subcontractors at the pre-qualification stage, and for assessing their performance at the construction stage. Tender price exerts the most significant influence in the subcontract award. A framework was developed for use by main contractors and consultants in the assessment of the suitability and performance of subcontractors. Application of the framework to a case study demonstrated its merit as a tool for ensuring that only high performing subcontractors are selected for subcontract jobs.