Fractures of the proximal femur are frequently seen in elderly people and will increase due to the demographic development of most industrialized countries. Early operation of dislocated fractures with either osteosynthesis or hemiprothesis has become a standard treatment for this type of injury. The high co-morbidity often leads to secondary complications like infections still resulting in a perioperative mortality rate of 11%. The perioperative infusion regime might influence the postoperative inflammatory response. Therefore Biseko(®), a serum protein solution, was compared to albumin and crystalloid infusion (Elomel). A total of 45 patients with proximal femur fractures were randomly assigned to either of the groups and received 500 ml of the infusion on 3 days starting from the day of operation. The Biseko(®) group showed significantly lower CRP levels, less infections and antibiotic treatment as well as a better clinical outcome referring to the TISS28 and APACHE Score. Concerning IL-6, IL-8, IL-10 and serum leukocytes no significant differences were observed. The result shows a beneficial influence of the serum protein solution Biseko(®) concerning the number of perioperative complications. The design of this study and the small number of patients does not yet allow any conclusion concerning the effectiveness of this treatment.