This study investigates service quality in the Greek Inland Revenue department. We examine differences in perceptions and expectations of service quality among tax-officers and tax-payers and identify the importance that service quality dimensions have for the above groups. One hundred eighty-one tax-officers and two hundred tax-payers completed a self-reported questionnaire. The analysis demonstrates citizen’s dissatisfaction of service quality. This is consistent with people’s impression of the efficacy of the public service and the low level of service-quality delivered. In terms of the five dimensions of service quality, reliability was rated as the most important dimension and tangibility as the less important one. Understanding citizen’s expectations of service quality will enable tax officers to identify practices in order to accomplish customer commitment and avoid future discontent.