Growing evidence suggest that interleukin-1beta (IL-1B) and interleukin-1 receptor antagonist (IL-1RN) are involved in the pathogenesis of schizophrenia. The objective of this study was to test the association of the functional promoter polymorphism 511T>C of the IL-1B gene and the VNTR polymorphism of the IL-1RN gene with clinical symptoms of schizophrenia. We studied 758 patients, 415 men and 343 women, with the ICD-10 diagnosis of schizophrenia. Symptoms of schizophrenia were measured using the Positive and Negative Symptome Scale (PANSS). The sample was stratified by gender and type of schizophrenia (chronic or episodic). We found the association between the VNTR IL-1RN polymorphism and PANSS negative symptoms (p = 0.02) in men. Male patients with the genotype 2*2 had lower scores than those with 1*2 and 1*1 genotypes. The genotype 2*2 was associated with a more severe illness course (shorter illness duration and smaller number of hospitalizations) as well. The results suggest that the VNTR polymorphism in the IL-1RN gene may be a predictor of outcome of schizophrenia in men.