Introduction: Occupational exposure to benzene and ethylbenzene has a serious impact on human health as they cause a wide range of health hazards ranging from irritation to carcinogenicity. In the literature, there is no enough data regarding the relationship between environmental levels of benzene and ethylbenzene and the biological monitoring data. This study aimed to measure the environmental levels of benzene and ethylbenzene and their metabolites in urine; and examine the possible relationship in between. Methods: A cross-sectional comparative study was carried out at a petroleum refining company in Egypt where 37 workers exposed to benzene and ethylbenzene were compared with 37 unexposed workers. Environmental levels of benzene and ethylbenzene were measured; workers were interviewed, and urine samples were collected to measure S-Phenyl mercapturic acid (SPMA) as benzene metabolite and mandelic acid (MA) and phenylglyoxylic acid (PGA) as ethylbenzene metabolites.