Objective To assess the perioperative hidden blood loss in aged patients with femoral intertrochanteric fracture.Methods Clinical data of 243 patients (111 males and 132 females) with intertrochanteric fracture admitted from 2009 September to 2015 September were retrospectively reviewed.Two hundred and seventeen patients aged 60-98 years received surgical treatment and 26 patients aged 62-91 years received conservative treatment (non-surgical group).In surgical group,17 cases were operated within 1 d after fracture,71 within 3 d,73 within 7 d,31 within 14 d,and 25 cases were operated after 14 d.Hidden blood loss was evaluated and blood routine was tested.Results The hidden blood loss was (340 ± 216) ml in non-surgical patients,(602 ± 216) ml in patients operated after 14 d,(671 ± 327) ml in patients operated 8-14,(596 ± 362) ml in patients operated 4-7 d,and (505 ± 119) ml in patients operated 2-3 d,(498 ± 244) ml in patients operated within 1 d;there was significant difference among groups (F =14.758,P =0.001).The hemoglobin level in non-surgical group was (121.8 ± 17.6) g/Lwithin 1 d after fracture,(101.1 ±23.3) g/L on 1-3 d,(91.5 ±31.9) g/L on4-7 d,(92.2 ±31.6) g/L on 8-14 d,and (108.3 ± 22.4) g/L after 14 d;there was statistically significant among groups (F =12.457,P =0.001).Conclusions Hemoglobin level in elderly patients with femoral intertrochanteric fracture is dynamically changed,and reaches the lowest point within 1-2 weeks after injury;and operation is an important factor of hidden blood loss in femoral intertrochanteric fracture patients.