Spontaneous tumour regression is a rare phenomenon in which there is a complete or partial regression of the primary tumour, clinically manifested by metastatic lesions. We report a case of a 34-year-old male with partial spontaneous regression of testicular seminoma detected by a supraclavicular lymph node biopsy. He underwent inguinal orchifunicolectomy. Based on the results of histological examination, against the background of multiple complexes of intratubular germ cell neoplasia in situ, foci of invasive growth and involution were identified, indicating a spontaneously regressing testicular tumour. We report the second case of a 52-year-old male with total spontaneous regression of testicular seminoma detected by a spermatic cord biopsy. Based on the results of histological examination, against fibrosis and proliferation of Leydig cells, there are atrophy of seminiferous tubules and complexes of intratubular germ cell neoplasia in situ in part of them.