The study covered workers of a chemical plant producing dust pesticides. A study group included 24 men, aged 29-54 years, employed directly in the production, and 22 women, aged 31-52 years, performing auxiliary jobs and handling only closed packages. In order to assess the renal function in the workers, the concentrations of serum creatinine and uric acid, protein, albumin and alpha 1-microglobulin, as well as the activity of alkaline phosphatase (AP) and N-acetyl-beta-glucosaminidase (NAG) in urine were determined. The average air dust concentration at the workplaces was 0.42-16.66 mg/m3. The active substances with concentrations ranging from 10 to 75% in the final product were as follows: triazines, dithiocarbamates, carbendazim and thiophanate-methyl, captan, phenylureas, cupric oxychloride and occasionally also carbamates, dodine and 2,4-D. As compared to the results in the control groups of 31 healthy men and 22 women, free from occupational exposure to chemical noxas, a significantly higher serum creatinine concentration (in none of the subjects creatinine concentration exceeded the upper normal limit) and higher urinary protein, albumin and alpha 1-microglobulin concentrations, and higher enzyme activity were found in men, while in women only urine enzyme activity was significantly increased. The results speak in support of a discreet subclinical kidney impairment.