The early effects of chronic low level exposure to gasoline vapours and organic solvents on kidney function have been difficult to identify. This study has attempted to identify markers, indicating a risk of kidney dysfunction, which might be useful tools for alerting occupational physicians to the early reversible changes so that preventive measures can be introduced to halt irreversible kidney damage. The exposed group in this study comprised 86 workers occupationally exposed to gasoline vapours and organic solvents in garages; the non-exposed group was 86 workers not occupationally exposed to the same substances. Exposed workers were matched with non-exposed by age and nationality. The mean age of the sampled population was 37.4+/-7.63 years. Current smokers formed 40.7% of the whole population and the percentages among exposed and non-exposed were broadly similar.