Introduction: Detecting possible organ donors is the most important step in the process of organ donation. However, the present approaches to this step don’t consider the setting of developing countries; despite their potential for high donation rates. Iranian Society of Organ donation (ISOD), previously introduced detectors as the pillars of the Persian possible donor detection program (PPDDP), a donation model designed specifically for cost-effective detection of possible donors (1). Now, 8 months after its introduction, PPDDP is implemented in the majority of Iranian provinces. Currently, we aimed to evaluate the effectiveness of detectors by finding a reliable measure for estimating the number of possible donors in each region.   
Methods: The present survey was conducted from Jun 2019-Jan 2020. All data regarding the detected possible donors were recorded on the national registry. Data regarding the number of detected possible donors, active detectors, active regular and ICU beds were extracted from the Registry. Additionally, the number of fatal road accidents and the population of each region were collected as well. The correlation between the number of possible donors and other variables was investigated through Spearman’s correlation coefficient. Multiple linear regression was used to model monthly possible donor detection rates considering the predictor variables.   
Results and Discussion: 37 of the 60 medical universities, the primary body responsible for transplant activities in each province, were included in the present study. Overall, 2378 possible donors were detected through the 8-month course of the present study. The monthly rate of possible donor detection was significantly correlated (p<0.0001) with the regional population, road accident fatalities and the number of detectors. The final regression model (R2=0.56, adjusted R2=0.54, p<0.001) showed that for every additional detector or any additional monthly rate of road fatalities in each region, the natural logarithm of the monthly detection rate of possible donors will be increased by 0.064 and 0.024 respectively. In other words, for every added detector to each province, monthly detected possible donors will roughly be increased by one. The number of ICU beds did not have a meaningful relationship with the number of monthly detected possible donors. 
Conclusion: The present study shows that the number of monthly detected possible donors can be reliably estimated through the number of fatalities from road accidents and the number of detectors, our newly introduced group for possible donor detection in PPDDP. As the cost of training detectors is significantly lower compared to transplant coordinators, the present study further confirms the cost-efficiency of using detectors for screening patients for possible donors.