External quality assessment is a standard procedure for many medical laboratories, especially those accredited according to ISO 15189. INSTAND has developed web-based quality control surveys (WQ) with integrated case-based learning in collaboration with the Institute for Teaching and Educational Research in Health Sciences (IDBG), University of Witten/Herdecke. The WQs were presented via a weblink using the learning management system CASUS. Laboratories registered with INSTAND for conventional EQAs covering the same topic were invited to participate in the WQs. Statistics were calculated with the INSTAND EQA-evaluation program and with the "Statistical Program for Social Sciences" (SPSS Version 20). While the two pilot surveys (hemostaseology) were designed for laboratory technicians, WQ III (urine sediment) addressed the whole laboratory team. From the invited laboratories more than 80% participated successfully and the evaluations showed that, in general, more than half the participants solved the tasks as a team. The web-based EQAs were well accepted by the users, with some technical problems in WQ III and moderate criticism on the images and relevance for daily practice in the evaluation sheets. Well above 80% would like to participate in further WQs and would recommend them to other laboratories. Thus web-based quality control surveys can emerge as an important supplement to conventional EQAs.