Background: Incidents with medical equipment have been observed by several studies [6, 4], and the lack of proper training has been identified as one of the main reasons for the occurrence of these errors . Providing proper training is costly and logistically problematic for hospitals. Simulations can successfully resolve some of these problems, as has been proven in aviation and surgeons' laparoscopic skills training. Aim: The aim of this study was to develop a simulation meant to train tasks related to operating medical equipment and to establish content-, face-, and concurrent validity for this simulation. Methods: An interactive simulation of an electrosurgical device was developed to enable users to practice procedural band cognitive tasks on a computer. This gives the users the ability to independently learn by doing. A total of 18 certified operating room nurses participated in this research. The participants were divided into two groups: (1) Simulation Trained (ST) and (2) Real life Trained (RT). The ST group received 2 training sessions with the simulation, whilst the RT group received a traditional hands on training. Before users (ST group) started using the simulation the goals, content, and features of the simulation were explained. Then they were asked to answer 16 structured questions concerning their first impression, training capacities, and statements regarding the simulation (face validity). These questions could be ranked on a mark ranging from 1 = very bad/useless to 5 = excellent/very useful) and the statements had to be answered with \agree", \disagree", or \no opinion". All participants were individually tested on their skills, related to en electrosurgical device, prior to, and after, having received their corresponding additional training. Errors were tallied and categorized into 3 types of errors: (1) connection, (2) identification, and (3) procedural errors, according to an assessment form. The results of the pre- and post test of ST group were compared with that of the RT group. Results: The results of the questionnaire show that the nurses rated the training capacities of the simulation and their first impression between a mean value of 4.0 for user friendliness and 4.4 for appearance and design of the software. In response to statements, 8 out of 9 participants (88%) considered this simulation useful for training procedural tasks related to the medical device, and all participants agreed that the simulation was useful to train identification tasks. All of the participants agreed with the statement that the simulation is suitable for training at home, whiles only 4 of the 9 (44%) learners agreed that the simulation is suitable for home use. During the experiment a reduction of 7 errors was observed for the ST group after having received the simulation training (p = 0.038). The RT group made 4 errors less after having received their additional training (p = 0.257). Conclusions: Content-, face-, and concurrent-validity of the developed simulation has been established. OR nurses considered the simulation useful for training tasks related to the electro-surgical device. Participants of the ST group significantly improved their performance, while this was not the case for the RT group.