Cytochrome P450 1A1 (CYP1A1) is an enzyme participating in the bioactivation of various endogenous and environmental reactive compounds that can bind to DNA and thus induce cancerogenesis. Gene encoding the enzyme is expressed in the prostate tissue and is polymorphic. CYP1A1*2A gene polymorphism is associated with elevated enzyme activity and/or inducibility which can lead to accumulation of genotoxic compounds and consequently to cancerogenesis. We examined the association of this polymorphism with prostate cancer (PCa) risk and aggressiveness. The case-control study consisted of 120 PCa patients and 120 benign prostatic hyperplasia (BPH) controls, in Croatian population. Regarding aggressiveness, PCa patients were grouped according to the Gleason score (GS), tumor stage (T) and existence of distant metastasis (M). The polymorphism was analyzed using real-time polymerase chain reaction (PCR). We did not observe association of mutated allele with PCa risk, neither with PCa aggressiveness. Furthermore, frequency of polymorphic genotype was slightly higher in BPH group (16.6% vs. 14.2%, respectively) and also in less aggressive form of PCa (20.4% vs. 9.6% for GS < 7; 15.6% vs. 9.1% for T < 3; 16.7% vs. 10.0% for no distant metastasis). Comparing our findings with other published results, we can assume that the ethnicity influence the genotype distribution and thus may affect the etiology of PCa, even possibly in the way to cause an opposite effect among different ethnic groups. Given the small number of participants, results should be validated on the larger sample size.