The aim of this study was to investigate the effects of the administrational supervision of occupational safety and health (OSH) inspectors in the workplaces that they inspect. In the questionnaire survey, the respondents were OSH managers and workers’ OSH representatives in the chemical companies’ plants. For workers, the aggregated variable ‘General OSH enforcement operations’ was positively related to the aggregated variable ‘Effects of the current OSH inspection’. In contrast, for the OSH managers, the corresponding data did not reveal any correlation. The professional competence in carrying out the OSH inspections was positively related to the different variables of the aggregated variable ‘Effects of the current OSH inspection (Outputs)’. In contrast, for the workers’ OSH representatives, the analysis failed to confirm this relationship. The present findings are that OSH managers and workers’ OSH representatives desired that the OSH inspector should follow up more effectively that OSH management systems are being implemented in practice. They should provide more advice to workplaces in order to help them to exceed the minimum level laid down by law. Workers’ OSH representatives expressed clearly that the OSH inspector should more often impose binding obligations. The professional skills of the OSH inspectors need to correspond better to the needs of today's working life and to be able to react to system changes in the workplaces. The OSH enforcement approach should become more uniform and be harmonized between the individual OSH inspectors and the OSH agencies. The development of the quality of OSH inspections and the professional competence of inspectors are important aspects from the point of the effectiveness.