Cotinine, as the main metabolite of nicotine, have been determined in urine using solid-phase extraction and high performance thin-layer chromatographic (SPE-HPTLC) method. The urine samples have been collected from the group of 35 male adolescents which were moderate or significantly exposed on the home environmental tobacco smoke (ETS). The 1-methyl-2-pyrrolidinone was used as the internal standard in proposed screening procedure. The thin-layer chromatograms were evaluated densitometrically after visualization of cotinine spots with ninhydrin and cadmium acetate solution. The described SPE-HPTLC procedure indicated good selectivity, sensitivity and reproducibility enabling reliable verification of interview collected questionnaire data in families exhibiting diversified level of ETS. The results of cotinine measurements by proposed method were applied for assessment of hazard from the home ETS on the health status of elementary schoolboys, especially an increased risk for infectious respiratory track diseases and exercise-induced bronchospasm.