A growing number of reports have revealed that microRNAs (miRNAs) play critical roles in spermatogenesis. Our previous study showed that miR-762 is differentially expressed in immature and mature testes of Large White boars. Our present data shows that miR-762 directly binds the 3' untranslated region (3'UTR) of ring finger protein 4 (RNF4) and down-regulates RNF4 expression. A single nucleotide polymorphism (SNP) in the RNF4 3'UTR that is significantly associated with porcine sperm quality traits leads to a change in the miR-762 binding ability. Moreover, miR-762 promotes the proliferation of and inhibits apoptosis in porcine immature Sertoli cells, partly by accelerating DNA damage repair and by reducing androgen receptor (AR) expression. Taken together, these findings suggest that miR-762 may play a role in pig spermatogenesis by regulating immature Sertoli cell growth.