Objectives: The aim of this work has been to find out the occupational oxidative stress, immunological and genotoxic health hazards among α-cypermethrin (CYP) pesticide-exposed workers. Material and Methods: A cross-sectional study was performed including 200 workers divided into 3 groups according to the level of exposure: highly exposed group (50 workers), moderately exposed group (50 workers) and unexposed group (100 workers). All workers were subjected to detailed laboratory investigation for gene P53 mutations, immunological parameters as a cluster of differentiation into 3 percentage (CD3%), CD4% and CD8% in addition to peripheral blood total leukocytic and platelet counts that were measured. Spectrophotometer technique was used for detection of superoxide dismutase (SOD), catalase (CAT), glutathione (GSH) and glutathione peroxidase (GPx). Air samples were collected with a High Volume Small Surface Sampler for measurement of α-cypermethrin level. Results: A highly exposed group to the α-cypermethrin had lower CD4/CD8 as compared to an unexposed group with statistically significant difference. As regards gene mutation, exons 5a and 6 were more frequent among the highly exposed group as compared to no mutation among moderately exposed and unexposed groups with significant difference. As regards antioxidants; SOD, CAT, GSH and GPx were higher among the unexposed group as compared to the highly and moderately exposed group with statistically significant difference. Significant negative correlation was found between working years and antioxidant parameters. Conclusions: Repeated exposure to α-CYP may lead to gene mutations, immunological disturbances and oxidative stress. Strict safety precautions are required not only for workers but also for public users. Int J Occup Med Environ Health 2017;30(4):603-615