We determined the frequency of graft-versus-host disease (GvHD) and overall survival (OS) in sex matched vs mismatched transplant.Medical records were analyzed of patients undergoing transplant from 2004 to 2016. Variables included age, sex of patient and donor, indication, conditioning regimen, stem cell source, frequency of GvHD and OS.We performed n = 162 allogeneic stem cell transplants. The most common conditioning regimen was busulfan/cyclophosphamide (n = 64). There was no difference in the frequency of GvHD in both groups. The transplant related mortality was higher (8.7%) in sex-mismatched transplants. The OS in both groups was similar.Our study showed higher transplant-related mortality in sex-mismatched transplant. There was no difference in GvHD and OS in both groups.