Objective  To evaluate the influence of optimized rehabilitation process on prognosis of old patients with Evans type III and IV femoral intertrochanteric fractures and investigate the related efficacy.  Methods  A retrospective case-control study was performed on 207 old patients with Evans type III and IV femoral intertrochanteric fractures fixed by proximal femoral nail anti-rotation (PFNA Ⅱ) in Peoples Hospital of Chongqing Banan District from March 2012 to January 2017. Normal rehabilitation group (n=100) had rehabilitation education and training after operation and started offbed exercise at postoperative 48 hours, including 38 males and 62 females, with age from 65 to 75 years in 69 patients and 75 years and over in 31 patients. There were 49 patients with Evans type III fractures and 51 with Evans IV fractures. Optimized rehabilitation group (n=107) had rehabilitation education and training at admission and started offbed exercise within 48 hours after operation, including 43 males and  64 females, with age from 65 to 75 years in 79 patients and 75 years and over in 28 patients. There were 63 patients with Evans III fractures and 44 with Evans IV fractures. Operation time, intraoperative bleeding, complications during hospital stay, fracture healing time, internal fixation rupture, femoral head cut, second fracture and mortality rate were recorded and compared between the two groups. Harris hip score was evaluated at postoperative 3, 6 and 12 months.   Results  All patients were followed up for 3-12 months, with the average of 11.6 months. Normal rehabilitation group showed introperative bleeding of (119.3±1.9)ml and operation time of (1.13±0.22)hours, which were not significantly differed from that in optimized rehabilitation group ［( 121.6±1.2)ml, (1.07±0.25)h］ (P>0.05). In normal rehabilitation group, the complications were hypostatic pneumonia in 19 patients, heart failure or acute myocardial infarction in 8, urinary infection in 18, lowerextremity deep vein thrombosis in 5, pressure ulcer in 4, with 5 deaths within 3 months after surgery. While in optimized rehabilitation group, the complications during hospitalization were hypostatic pneumonia in 6 patients, urinary infection in 6, heart failure or acute myocardial infarction in 1, lower-extremity deep vein thrombosis in 1, pressure ulcer in 0 during hospital  (P<0.05). Within 3 months, mortality rate was 5% in normal rehabilitation group compared to zero in optimized rehabilitation group (P<0.05). At postoperative 3 months, 6 months and 12 months, Harris hip scores in optimized rehabilitation group［(69.7±6.3)points, (80.2±4.6)points, (89.3±10.2)points］ were significantly higher than that in normal rehabilitation group ［(53.6±5.4)points, (75.1±9.2)points, (77.5±7.5)points］(P<0.05). Fracture healing time, internal fixation rupture, femoral head cut, second fracture and mortality rate at postoperative 12 months had no significant differences between the two groups (P>0.05).Conclusion   Optimized rehabilitation process can improve hip function, reduce complication rate and mortality rate at postoperative 3 months in old patients with Evans type III and IV femoral intertrochanteric fractures, which deserves clinical application.