The synthesis of a,߭unsaturated and arylnitriles is of great interest to synthetic chemists, since the nitrile functionality has unique reactivity and is relatively easy to introduce. The characteristic reactivity of nitriles makes them particularly suitable for the construction of heterocyclic compounds as well as other highly functionalized molecules. This chapter presents a variety of the methods that are available for the synthesis of a,߭unsaturated and arylnitriles. Starting with a general overview of the synthesis of the a,߭unsaturated nitrile moiety, the review then concentrates on those methods that are most commonly employed in the synthesis of a,߭unsaturated nitriles. Particular attention is given to advances in the field of a,߭unsaturated nitrile synthesis since the 1990s. The synthesis of aryl- or heteroarylnitriles is then presented, again with a general overview of common methods as well as more recent advances in this area. Finally, there is a brief description of the synthesis of nitriles bearing an a,߭triple bond.