Bicornuate uterus consists of about 20% of uterine anomalies and is caused by the defect in the fusion of the m llerian ducts. In many cases, it is asymptomatic and is not detected clinically. But it can cause several fertility problems, ranging from infertility and recurrent abortions to prematurity and malpresentation. We have experienced a case of pregnancy in bicornuate uterus that expelled decidual cast and delivered of a female baby 3 weeks later. We present this case with brief review of literatures.