Background To compare the clinical results and complications between endoscopic and microscopic techniques in 247 patients with pituitary tumors.Methods We performed a retrospective review of 100 patients underwent endoscopic endonasal transsphenoidal surgery(ETS)and 147 patients underwent microscopic transsphenoidal surgery(MTS)at our center between Jan 2007 to July 2014.Tumors were stratified by Knosps classification and modified Hardys classification.Tumor gross total resection(GTR)/remission rate,visual improvement rate,complications,operation time,intraoperative bleeding and hospital stay were compared between each subgroup.Results Knosp grade was statistically significant variable for GTR rate in both groups(P<0.05).The GTR rate in ETS and MTS group was 93.3%versus 82.8%in knosp grade 0,87.5%versus 92.0%in grade,71.4%versus 70.7%in grade Ⅱ and 58.8%versus 36.0%in grade Ⅲ.There was no attempt to achieve GTR in all Knosp grade Ⅳ tumors in both treatment groups.The visual field improvement rate between ETS and MTS group was 66.7%versus 45.5%in Hardy grade B,72.2%versus 71.4%in grade C,and 88.9%versus 78.9%in grade D.There wasno significant difference in GTR rate,visual outcomeand complication ratebetween two groups(P>0.05).There was larger intraoperative blood loss(P=0.000),longer operative times(P=0.024),but shorter hospital stay(P=0.000)in ETS group.Conclusions ETS need a longer operation time and lead to larger intraoperatie blood loss.But there is trend for higher resection rate in pituitary tumors with knosp grade Ⅲ-Ⅳ.Further studies with large multicentric cohorts are warranted.