This paper presents a synthetic summary of the literature in the area of quality of e-government services, as a basis for the future construction of a relevant model and ontology. We include 18 different approaches concerning quality of service for public sector in general and e-government more specifically. Using as a criterion the focus of each approach on organizational issues or the front end of the service we classified them in introvert and extrovert ones. As a result of the review we were able to organize the main components influencing quality of e-government services in the following four key areas: service, content, system and organization.