The present article offers a mixed-method perspective on the investigation of determinants of effectiveness in quality assurance at higher education institutions. We collected survey data from German higher education institutions to analyse the degree to which quality managers perceive their approaches to quality assurance as effective. Based on this data, we develop an ordinary least squares regression model which explains perceived effectiveness through structural variables and certain quality assurance-related activities of quality managers. The results show that support by higher education institutions' higher management and cooperation with other education institutions are relevant preconditions for larger perceived degrees of quality assurance effectiveness. Moreover, quality managers' role as promoters of quality assurance exhibits significant correlations with perceived effectiveness. In contrast, sanctions and the perception of quality assurance as another administrative burden reveal negative correlations.