In a city like Dubai, where one of the biggest and fastest growing construction markets in the world exists, the need to estimate the cost of quality in the construction projects becomes a vital task. This research used the prevention–appraisal–failure (PAF) model to evaluate the cost of quality (CoQ) and to determine its optimum value – the level of quality that minimizes the total CoQ – for the residential construction projects in Dubai. The results revealed that the CoQ in such projects in Dubai represents 1.3% of the total project civil work cost and that the optimum CoQ value was estimated to be 1.34% of the total CoQ. Failure costs, on the other hand, were estimated to be .7% of the project cost.