Patients who receive allogeneic blood transfusions after orthopedic surgery have a longer duration of hospitalization, and this cannot be explained by a more frequent incidence of infections in transfused patients. To determine whether transfusion of allogeneic blood interferes with wound healing and therefore increases the duration of hospitalization, we performed an observational study in 444 consecutive patients scheduled for elective primary hip surgery. Transfusion, wound, and infection variables were collected at five time points during treatment. Of the 444 consecutive patients studied, 92 received blood transfusions during their perioperative course. Thirty-one percent of transfused patients developed wound-healing disturbances versus 18% of the nontransfused group (P < 0.05); allogeneic blood transfusion was the only significant predictor for development of minor wound-healing disturbances. Duration of hospitalization was prolonged in transfused patients (12.3 versus 9.8 days) and could be predicted by 4 significant variables: requirement for blood transfusion (adds 2.7 +/- 0.5 days), presence of wound-healing disturbances (adds 1.3 +/- 0.5 days), duration of surgery (adds 0.2 +/- 0.1 days/10 min), and patient's age (adds 0.9 +/- 0.2 days/10 yr). These data suggest that allogeneic blood transfusion is associated with an increased incidence of wound-healing disturbances and that prevention of allogeneic blood transfusion may be relevant in limiting the duration of admission after elective orthopedic surgery.