Electronic Co mmerce (E-Co mmerce) has a growing potential in Saudi A rabia, due to widespread use of the internet and the maturity of the Information Technology (IT) infrastructure. The purpose of this paper is to assess the quality of E-Co mmerce websites in Saudi Arabia, using a proposed evaluation instrument. To achieve this aim, six E-Co mmerce websites were selected for evaluation and then categorized into three categories: domestic, reg ional and international. Each category consisted of two E-Co mmerce websites, with the international website category considered as a benchmark. The six websites were evaluated by sixty participants (n=60) with good web design experience, following a set of guidelines offered by the evaluation instrument. The evaluation instrument described six key evaluation factors: appearance, content, organization, interaction, customer-focus and assurance. Each factor was evaluated by several indicators using a five-point scale ranging fro m not applicab le (0) to very strong (4). To unify the views of all evaluators, a technique was introduced which would show the way in wh ich each indicator was assessed based on several checklists (questions). The results therein revealed that international websites were of h igher quality than regional and domestic websites with regard to all aspects of web evaluation. In addition, the quality of regional websites outweighed that of domestic websites with regard to appearance, content, organization, customer-focus and assurance, but not interaction.