Dietary aflatoxins produce a disease state known as aflatoxicosis, and disruption of spermatogenesis is one of its serious consequences. Towards finding the cellular targets in spermatogenic compartment for aflatoxin toxicity, aflatoxin B(1) (AFB(1)) was administered to 90-day-old Swiss mouse through i.p. route at a daily dose of 20mug per kg body weight for 7, 15, 35 and 45 days. The testis and epididymis were subjected to light- as well as transmission electron microscopic analysis. One of the newer observations was occurrence of meiotic micronucleate giant spermatocytes in seminiferous epithelium and epididymal lumen. The origin of these cells could be traced to imminent disruption of spindle apparatus during meiotic division of spermatocytes, resulting in lagging of chromosome bivalents or replicated univalents. Such chromosomes appeared to undergo condensation and become micronuclei. Thus, this study reports that aflatoxin exposure would result in generation of meiotic micronucleate giant spermatocytes.