The vertical distribution of acetonitrile between 0 and 55 km altitude is calculated assuming that CH3 CN is released at the Earth's surface and that the main loss process in the stratosphere is the reaction with hydroxyl radicals. The influence of different possible surface concentrations is investigated. The role of the destruction of CH3CN by Cl, as well as the use of different eddy diffusion coefficients is briefly discussed. The results are compared with recent measurements of acetonitrile.