BACKGROUND The prevention of occupational diseases is limited by a lack of insight into occupational exposure to risk. We developed a six-step approach to improve the diagnosis and reporting of occupational diseases and the selection of subsequent preventive actions by occupational physicians (OPs). AIMS To evaluate the effect of the six-step approach on the transparency and quality of assessing occupational diseases and the usability of the six-step approach according to OPs and their satisfaction with it. METHODS A randomized controlled trial. OPs in the control group used the standard information available. OPs in the intervention group used the six-step approach and accompanying educational materials. The actions and decisions of OPs in both groups were analysed using 17 performance indicators. To address the second issue, OPs used the six-step approach over 6 weeks and rated its usability and their satisfaction in relation to several aspects. RESULTS The average score of the OPs in the intervention group (n = 110) was statistically significantly higher (11/17 performance indicators, 62% of the maximum score) than that of the OPs in the control group (n = 120, 5/17 performance indicators, 30% of the maximum score, P < 0.001). The usability aspects of the six-step approach had mean scores of 7 and 8. Mean satisfaction with the six-step approach was 8. CONCLUSIONS The six-step approach resulted in better evidence-based and transparent decision-making about occupational diseases by OPs. Usability and satisfaction were rated as satisfactory by the OPs.