Abstract: The aim of the present study is to analyze the effect of different doses of endosulphan on spermatogonia of Capra hircus in vitro. Small pieces (approximately 1 mm3) of testicular tissue were divided into two groups (one experimental group and one control group). Experimental group was treated with different concentrations of endosulphan (1x10-3, 1.0 and 100 nmol mL-1) and was further divided into three subgroups (1), (2) and (3) exposed for 1, 4 and 8 h, respectively. The endosulphan exposure revealed increasing morphological alterations with increasing dose of endosulphan in spermatogonia. At dose level 1x10-3 nmol mL-1 of endosulphan, light microscopic changes in spermatogonia were characterized by condensed nuclei which were darkly stained with haematoxylene eosin. Hyalinization and chromolysis, vacuolization in spermatogonia were clearly observed. Vacuolization in spermatogonia were also enhanced as the exposure duration extended. Endosulphan at concentration level 1x10-3 nmol mL-1 induced decline in spermatogonial diameter from 7.245±0.201 in control to 6.75±0.231 μm after 1 h, 6.5± 0.2115 μm after 4 h and 6.45±0.2233 μm after exposure duration of 8 h. At the same dose level of endosulphan atretic spermatogonia were 34, 44 and 52% after exposure duration of 1, 4 and 8 h, respectively. Due to increase in the endosulphan concentration upto 100 nmol mL-1, atretogenic changes induced in spermatogonial cells were characterized by increased fragmentation and pycnosis of nucleus. Ultrastructurally, chromolysis, vacuolization, hyalinization, condensation of nucleus, apoptotic vacuoles and shrinkage of cytoplasm was generally observed. These changes were prominent at higher dose level and extended exposure duration.