PURPOSE: To produce the titled compound useful as an intermediate of antiulcer agent, etc., in high yield, by heating hexahydroterephthalic acid and urea available at a low cost and handleable easily, at a specific temperature.

CONSTITUTION: 4-Cyanocyclohexane-1-carboxylic acid is produced by heating hexahydroterephthalic acid and urea at 230W350°C, preferably 250W310°C. If the temperature is lower than the above range, the reaction becomes slow, and if it is higher, the production of by-product is accelerated. The amount of urea of 0.5W10mol, preferably 2W5mol per 1mol of hexadhydroterephthalic acid. The unreacted component can be reused as the starting material, and the raw material can be converted to the objective compound without loss.