Challenges like employees' psychological strain and organisational changes have forced governments and organisations to define new major procedures in governmental section. These changes should be reviewed especially for POLICE employees who are under the pressures and STRESSes from their policing job. The present study is intended to identify the occupational STRESSes and their intra-organisational and inter-organisational effects in preventive POLICE of the Islamic Republic of Iran (IRI). This is a descriptive heuristic study based on an applied goal and a statistical population consisting of senior officers (Senior Management) of preventive POLICE of IRI. A total of 230 people of the population were randomly selected from all over the country. After interviewing the seniors and commanders and completing the questionnaires, the results were analysed by PLS and SPSS software packages. The findings showed that the variables were a combination of internal and external factors and R2 was equal to 0.821, so the value of R2 is correct and therefore the constructed model is validated. According to the results, the hypothesis that the two intra-organisational and inter-organisational factors can impact the STRESS level of the POLICE employees is confirmed and after ranking, intra-organisational factors showed greater impacts on the STRESS levels as compared to the inter-organisational factors.