This paper puts forward emerging theory on determining factors for quality of educa- tion in private higher education institutions. A model of factors and sub-factors that influence the quality of education, result of in-depth interviews with leading figures of the institutions, is presented. The study was conducted with a sample of twenty-two leading figures of private higher education institutions, using a Delphi methodology or expert consultation, and it reveals an up- date of Arcaro’s model of 1995.