The present study was conducted to investigate the effectiveness of Istanbul University Virtual Laboratory (IUVIRLAB) electromagnetic field and magnetism experiments on undergraduate students' understanding of electromagnetic field and magnetism concepts and to determine the students' misconceptions about electromagnetic fields and magnetism. IUVIRLAB has unique characteristics in terms of being a 3-dimensional, interactive virtual laboratory that enables students to learn in cooperative groups, and is the first of its kind due to its qualities of enabling multi-admin and multi-user operation, having special software compatible to run on iPad, iPhone, android and smart phone platforms, and having been designed on the basis of active learning approaches. To determine 120 (n=60 experimental and n=60 control groups) students' misconceptions about electromagnetic fields and magnetism and the effectiveness of IUVIRLAB, Magnetic Field Concept Test consisting 20 items was used as a pre-test and post-test. According to the results, twenty-four misconceptions about electromagnetic field and magnetism were identified. The results from the paired sample t-test indicated that the students who were instructed using IUVIRLAB instruction had significantly higher scores in terms of achievement than those taught by the traditional approach and it was also found that IUVIRLAB group was more successful in preventing of the determined misconceptions. (C) 2015 The Authors. Published by Elsevier Ltd. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).