Aim : The purpose of this analysis was to compare simple pertrochanteric fractures (PTFs) AO31-A1.2 and PTFs with the detachment of lesser trochanter AO31-A1.3 along with the risk factors of perioperative blood loss in terms of their impact on postoperative level of hemoglobin. Methods : This study analysed the clinical data of 334 unilateral, stable PTFs classified as AO31-A1.2 (205 cases) and AO31-A1.3 (129 cases) treated with proximal femoral nail antirotation (PFNA). First postoperative level of hemoglobin and hemoglobin drop (difference between first on admission to hospital and first postoperative hemoglobin levels) were chosen as the principal outcome. Analyzed patients were not transfused between hemoglobin measurements. Multivariate linear regression analysis was performed to study perioperative blood loss risk factors in patients undergoing surgery. Results : Pertrochanteric fractures with the detachment of lesser trochanter (AO31-A1.3) are associated with both greater hemoglobin drop (p=0.011) and lower postoperative hemoglobin level (p=0.078). AO31-A1.3 type of fracture is also correlated with greater risk of postoperative blood transfusion (p=0.038). Female were associated with lower postoperative hemoglobin than men irrespective of the type of fracture (9.31 g/dl vs 10.1 g/dl; p<0.0001). Multi linear regression analysis showed that age, gender, type of fracture, fracture gap displacement, preoperative level of hemoglobin and angle of the fracture gap significantly affect postoperative level of hemoglobin. Conclusion: Despite being recognized as stable PTF with the detachment of lesser trochanter (AO31-A1.3) is burdened with greater risk of postoperative anemia and blood transfusion than simple PTF (AO31-A1.2). Fracture gap displacement and angle of fracture gap are useful predictors for lower level of postoperative hemoglobin.