Little is known about the fate of polybrominated diphenylethers (PBDEs) across the Oceans. Air and water were sampled using both active and passive polyethylene samplers on an east-west transect across the tropical Atlantic Ocean in 2009 and analyzed for PBDEs. Typical particle-bound concentrations of PBDEs in the surface water were low, at <1 pg L(-1). Truly dissolved concentrations from passive samplers were ∼0.5 pg L(-1) for BDE 47 and around 0.1 pg L(-1) for BDEs 28, 99, and 100 (results from active samples were compromised). In the atmosphere, particle-bound BDE 209 dominated overall concentrations (median 1.2 pg m(-3)), followed by BDE 99 (0.13 pg m(-3)). Gas-phase concentrations based on passive samplers were 1-8 pg m(-3) for BDE 47 and ≤ 4 pg m(-3) for BDE 99. Net air-water exchange gradients strongly favored gas-phase deposition of PBDEs into the water. Net gas-phase deposition fluxes ranged from tens of pg m(-2) day(-1) for BDEs 28 and 85 to around 1 ng m(-2) day(-1) for BDE 47, 99, and 209. Settling fluxes of particle-bound PBDEs in the atmosphere and surface water were around 50 pg m(-2) day(-1) for BDE 47 and <10 pg m(-2) day(-1) for the other congeners.