Hypoplasia refers to testicular disorders related to congenitally underdeveloped and underactive spermatic epithelium of one or both testes even though the interstitial tissue is normal. Clinically, the scrotum in both cases is small and the affected testis feels flabby with ejaculates containing few or no sperms. Males suffering from the bilateral condition are always sterile while in those possessing unilateral hypoplasia the unaffected testis can produce normal semen. Conditions of hypoplasia were recorded by several researchers in Indian cattle and buffalo breeds. Though overall incidence of hypoplasia is not high in buffaloes, unilateral hypoplasia is generally seen in about 5% of buffalo bulls with incidence of bilateral testicular hypoplasia being much lower (about 2.5%). In hypoplastic condition of testis, libido and coitus remain unaffected but conception rates are very poor. Bulls suffering from hypoplasia should not be used for breeding since this condition is hereditary and caused by single autosomal recessive gene.