Rose fragrance, containing many kinds of volatile compound, is widely applied in the textile and cosmetics industry. If it can be encapsulated into polymer materials, the duration of its aroma can be extended for a much longer period. Microcapsules cannot be firmly fixed on the fibres, due to their size limitation. However, encapsulating fragrance in nanocapsules could avoid the evaporation of volatile components and prolong the service life of aromatic textiles. In this study, polybutylcyanoacrylate (PBCA) with excellent biocompatibility and biodegradability was used to encapsulate rose fragrance to form nanocapsules via anionic polymerization. The mean diameter of the nanocapsules was 67.3 nm and the encapsulation efficiency was 65.83% with 0.8% BCA, 0.5% rose fragrance, 2.6% polyoxyethylene(20) sorbitan monolaurate (Tween-20), <pH 2. Transmission electron microscopy (TEM) showed that the size of spherical nanocapsule varied in the range 30-100 nm. Fourier transform infrared spectrometry (FTIR) demonstrated that BCA had been completely polymerized and could interact with rose fragrance via the hydrogen bonds. Gas chromatography-mass spectrometry (GC-MS) showed that the washing resistance of cotton fabrics finished by 67.3 nm nanocapsules was much better than that by rose fragrance alone. Both GC-MS and UV analysis displayed that the loss of the fragrance released from cotton fabrics finished by 67.3 nm nanocapsules was obviously lower than that by 339 nm nanocapsules and rose fragrance. Nanoencapsulation by PBCA of the fragrance by anionic polymerization appears to be an effective technique for fragrance encapsulation, providing a well-sustained release property. The smaller the nanocapsule size, the better the sustained release property. Copyright (C) 2011 John Wiley & Sons, Ltd.