The relative basicity of a series of nitriles in the gas phase, chloroform, and aqueous solution is studied using ab initio and state of the art SCRF methods. Theoretical results reproduce well the available experimental data for a large series of nitrile derivatives. The origin of basicity differences in solution within the series is analyzed. The impact of the results in the understanding of nitrile chemistry is discussed. * To whom correspondence should be addressed. † Institut Químic de Sarrià, Universitat Ramon Llull.