The purpose of this paper is to develop an analytic hierarchy process (AHP) approach to measure service quality in e-commerce environments. First, an e-commerce service quality (ESQ) index system was constructed. AHP was then carried out to find the relative weights of those assessment criteria and sub-indicators. According to the results, the weights for the three criteria are ordered as website design, responsiveness and information quality. In addition, the most important three sub-indicators are safety in online transactions, easy to use website and delivering services on time. Using an empirical example, the quality scores of the nine sub-factors and the global service were calculated according to the perceptions of customers. The proposed model and method can be tailored and applied by e-commerce enterprises to evaluate their service quality and identify which service dimensions or sub-indicators require most efforts in order to create better service.