The increasing trend of deaths and injuries in industries has led their authorities to develop accident investigation plans. One of the underlying aspects of such plans is hazard identification and incidents reporting which can be met by an appropriate employees' participation. So far, several studies have confirmed the effect of training in participation improvement. So the main objective of the present study was to compare two training approaches, classic and creative, in improving health, safety and environment (HSE) supervisors' participation. The study was carried out in an Iranian petrochemical complex where the safety supervisors had been encouraged to report incidents through the Green Card system. Classic and creative training approaches were applied to increase supervisors' participation. To do so, the supervisors were divided into Case and Control groups. In order to determine the level of supervisors' participation, the mean of completed green cards by each person at six month intervals was used. In this way, the level of participation in the two groups was measured before, during and after the intervention. To analyze the results, Student's t-test, Longitudinal Data Analysis and Mixed Model were employed. The results showed that both during and after the intervention, the effect of the creative approach was more than that of the classic approach. After twelve months of intervention stop, the participation trend in both groups was downward. However, this decrease was only significant in the control group. To conclude, the creative approach emphasizing on the participatory training could be an effective approach in improving the safety and consequently the health of supervisors in industries. (C) 2011 Elsevier Ltd. All rights reserved.