Two new indices, the sperm deformity and the sperm multiple anomalies index, were assessed in 16 male patients who underwent unilateral orchectomy owing to seminoma and in preventive radiotherapy of paraortic and of the iliac lymph glands homolateral to the testis excised. The aim was to assess the value of these two morphological sperm parameters in distinguishing the semen between the above mentioned group of men from the semen of men with other causes of infertility. It was found that: (1) the values of the sperm deformity index and those of the sperm multiple anomalies index were not significantly different between men who underwent unilateral orchectomy and preventive radiotherapy and the men with other causes of subfertility and (2) the values of the above indices were significantly higher in the semen specimens of men who underwent unilateral orchectomy and preventive radiotherapy and in the semen specimens of men with other causes of subfertility than in the semen specimens of fertile men. It is concluded that testicular response, as far as sperm morphology is concerned, is the same irrespective of the cause exerting a negative effect on spermatogenesis.