We have investigated the adsorption properties of acetone on zigzag single-walled BNNTs using density functional theory (DFT) calculations. The results obtained show that acetone is strongly bound to the outer surface of a (5,0) BNNT on the top site directly above the boron atom, with a binding energy of -96.16 kJ mol(-1) and a B-O binding distance of 1.654 Å. Our first-principles calculations also predict that the ability of zigzag BNNTs to adsorb acetone is significantly stronger than the corresponding ability of zigzag CNTs. A comparative investigation of BNNTs with different diameters indicated that the ability of the side walls of the tubes to adsorb acetone decreases significantly for nanotubes with larger diameters. Furthermore, the stability of the most stable acetone/BNNT complex was tested using ab initio molecular dynamics simulation at room temperature.