In a process for producing a nitrile compound comprising introducing a carbon ring or heterocyclic compound having organic substituents, ammonia and the air into a reactor and reacting the introduced compounds in the presence of a catalyst, during the reaction, a residual gas obtained after the formed nitrile compound is separated from a reaction gas discharged from the reactor is recycled to the reactor in an amount of 10 to 60% by volume based on the amount of the fresh raw material gas supplied to the reactor and the ratio of the amount by mole of molecular oxygen to the amount by mole of the organic substituent in the carbon ring or heterocyclic compound having organic substituents supplied to the reactor (O.sub.2/organic substituent) is kept within 1.5 to 7. The reaction is achieved under an advantageous condition and the nitrile compound can be produced industrially advantageously at a higher yield.