Based on a series of 32 cases of late recurrence of early stage vocal cord cancer, the question of the pathogenesis of these lesions is discussed. Late recurrence, 5 to 18 years after treatment of the first tumour was observed in 3 cases after a laryngofissure procedure only and in 29 cases after laryngofissure combined with postoperative irradiation or after pure irradiation therapy. The clinical and statistical data and the histological picture of the second tumour show with a high degree of certainty that these second tumours are caused by the cancerogenic side-effect of the primary irradation, which destroyed the primary tumour. The danger that a patient, cured from his first cancer by irradiation, develops a second radiogenic cancer rises from year to year that the patient survives and certainly is much higher than had been suspected. Irradiation of a vocal cord cancer in a young patient with a relatively high life expectancy should no longer by used. Irradiated patients must be reviewed until the end of their lifes.