Avian polyomavirus (APV) infection causes various health problems in psittacine species, including death. The present study was conducted to investigate the prevalence of APV among psittacine birds in Iran. We also aimed to evaluate the impact of age, sex, species, season, and origin of the birds on the prevalence of APV. This study investigated the presence of APV among 1050 individual birds from 7 psittacine species over a 1-year period in Iran, namely, green-cheeked parakeets (Pyrrhura molinae), rosy-faced lovebirds (Agapornis roseicollis), monk parakeets (Myiopsitta monachus), sun conures (Aratinga solstitialis), Senegal parrots (Poicephalus senegalus), cockatiels (Nymphicus hollandicus), and grey parrots (Psittacus erithacus). The overall prevalence of APV in all studied species was 25% (263/1050, 95% confidence interval [CI]: 22.5–27.8). Results of the study showed that age and the season of the year were 2 important determinant factors in the prevalence of APV in psittacine birds. Young psittacine birds <6 months old were 2.94 (95% CI: 1.19–7.27) times more likely to be infected with APV than birds >1 year old, and there was a significant interaction between season and species in the multivariate analysis. In the winter season, rosy-faced lovebirds and green-cheeked parakeets were 15.6 (95% CI: 4.20–57.95) and 4.76 (95% CI: 1.4–16.21) times more likely to be infected with APV than in other seasons, respectively. This is the first report on the detection rate of APV in psittacine birds in Iran.