Objective To compare intramedullary nailing assisted by minimally invasive cerclage with simple intramedullary nailing in the treatment of femoral long oblique subtrochanteric fractures.Methods From April 2010 to September 2015,our department treated 39 patients with femoral long oblique subtrochanteric fracture.Of them,16 were treated by cephalomedullary nailing combined with minimally invasive cerclage (observation group of 11 males and 5 females with an average age of 42.8 ± 13.2 years) and 23 by simple cephalomedullary nailing (control group of 17 males and 6 females with an average age of 46.2 ± 10.1 years).Their operation time,intraoperative blood loss,radiologic results (union time and alignment) and functional results [Visual Analog Scale (VAS) and Harris hip score] were compared between the 2 groups.Results The 39 patients were followed up from 12 to 30 months (average,15 months).For the observation group,the varus angle (2.2°± 1.4°) was significantly smaller than for the control group(4.1°±2.2°),the VAS scores at 1 and 3 months postoperatively (3.43 ± 1.54,1.13 ± 1.20) were significantly lower than for the control group (5.61 ± 1.41,3.34 ± 1.82),and the clinical union ratio at 3 months postoperatively(87.5％,14/16) significantly higher than for the control group (47.8％,11/23) (P ＜ 0.05).There were no significant differences between the 2 groups in terms of operation time,intraoperative blood loss,Harris hip score at one year postoperatively,VAS score at 6 months postoperatively,or clinical union ratio at 6 or 12 months postoperatively(P ＞ 0.05).Conclusions Cephalomedullary nailing is effective for the treatment of femoral long oblique subtrochanteric fractures no matter it is assisted by minimally invasive cerclage or not.However,since minimally invasive cerclage has the advantage of improving reduction and mechanical stability,combination of minimally invasive cerclage and cephalomedullary nailing may be more advantageous in early pain-relieving and functional recovery.