The purpose of the project was an assessment of psychometric characteristics of the WHO Neurobehavioral Core Test Battery (NCTB) (in traditional version) and the Hanninen Subjective Symptom Questionnaire adapted for Poland. The subjects were 119 greenhouse workers, 65 of them were exposed to organophosphorous pesticides and 54 were nonexposed ones. To assess the reliability, all tests from NCTB were administered twice with a 4-month interval. The results obtained in the first examination were used to determine the effects of gender, age, and education on tests performance. To determine the underlying factor structure of the test battery, the factor analysis was performed on 45 variables. The test-retest reliability coefficients ranged from 0.33 to 0.91. The lowest correlations were found for the Aiming Test--sum of errors (r = 0.33) and the Benton Test (r = 0.34). Gender appeared to be the most modifying factor of test performance. The factor analysis yielded 11 factors with eigenvalues greater than 1.0 (78.4% of variance explained).