Objectives: To evaluate the effect of anti-tuberculosis drugs (ATD) on indices of reproductive capability, DNA fragmentation and offspring development of male rats with testicular malfunction caused by experimental diabetes. Materials and Methods: Wistar albino male rats (body weight 160-200 g) were divided into three groups: I - control, II - streptozotocin diabetes, III - streptozotocin diabetes + ATD. The testis DNA fragmentation was determined electrophoretically; spermatogenetic indices, offspring antenatal and postnatal development indices - by standard procedures. Morphological analyses of gonadic structures were carried out by optic microscopy. Results: The study of the effects of diabetes and ATD administration on testis cells morphologic and morphometric parameters and spermatogenesis suggested the presence of specific diabetes- and anti tuberculosis drugs - mediated quantitative and qualitative changes in male rat reproductive organs, spermatogenetic epithelial cells, level and character of DNA fragmentation in comparison with normal rats. These changes were accompanied by alterations in processes of fertilisation (with intact females), embryogenesis and by lowering of offspring survival. Conclusions: Observed changes could hence affect the state and correct functioning of spermatogenetic epithelium and of other tissues of reproductive organs, as well as offspring development in diabetic rats.