The aim of this study was to investigate the relationship between gene Period3 (Per3) variable number tandem repeat (VNTR) polymorphism and chronic heart failure (CHF).The study subjects (372 patients of Caucasian origin with CHF and 332 healthy controls) were genotyped for Per3 VNTR polymorphism using an allele-specific PCR.No significant differences in genotype or Per3 VNTR allele frequencies were found between CHF cases and controls (Pg=0.30, Pa=0.52). No significant differences were uncovered either between CHF cases according to etiology (DCMP vs. IHD; Pg=0.87, Pa=0.91). In the multivariate regression modeling, no predictive function of VNTR Per3 polymorphism on ejection fraction or NYHA class, hyperlipidaemia or type II diabetes risk was found.Per3 VNTR polymorphism is not a major risk factor for chronic heart failure or a factor modulating the severity of the CHF in this population.