Air samples were collected both at an urban and an industrial area of Florence (Italy) in order to evaluate the occurrence, profiles, seasonal variation and gas/particle partitioning of polybrominated diphenyl ethers (PBDEs). The mean total (gas + particle phase) PBDE concentrations were 42.8 ± 7.8 and 89.0 ± 21.1 pg/m3 in the urban and industrial sites, respectively. In all samples, BDE-209 was the most abundant congener, followed by BDE-47 and BDE-153 in the industrial site, and by BDE-99 in the urban site. The Σ6PBDE (sum of BDE-28, -47, -99, -100, 153, -154) concentrations in the urban (12.1–27.9 pg/m3) and industrialised (21.4–44.3 pg/m3) sites were comparable to, or slightly lower than measured at other sites. The partition coefficient of PBDEs between the gas and particle phases (Kp) was well correlated with the subcooled liquid vapor pressure (P°L) for all samples. The measured particulate sorption of PBDEs was compared to the predictions from Junge-Pankow (J/P) model and KOA absorption model. While the Junge-Pankow model tends to overestimate the particulate sorption, the KOA based model seemed to fit the PBDE data.