Objective: To explore the association of genetic polymorphisms in the genes encoding the anti-Müllerian hormone (AMH) and its type II receptor (AMHRII) with ovarian hyperstimulation syndrome (OHSS). Methods: Using polymerase chain reaction (PCR) and DNA sequencing techniques, the exons of AMH and AMHRII were analyzed in 27 OHSS patients (OHSS group) and 22 non-OHSS patients (control group) who were applied controlled ovarian hyperstimulation (COH). Single nucleotide polymorphisms (SNPs) were also analyzed. Results: SNPs G>T at position 146 of AMH exon 1 and G>A at position 134 of AMH exon 2 showed significant differences between the OHSS group and control group (P<0.05). SNP G>T at position 303 of AMH exon 1 showed no significant difference between the OHSS group and control group (P>0.05). No SNP was detected from the AMHR II exons 1 to 11 in either groups. Conclusions: Genetic polymorphisms in the AMH gene may be a cause of ovarian hypersensitivity to exogenous hormone stimulation and the development of OHSS. © 2013 The Editorial Board of Journal of Reproduction and Contraception.