The relationship between the number of red blood cell transfusions and major infectious complications was evaluated in 594 thermal injury patients admitted between 1982 and 1986 who had burns over 10% or more of total body surface area and survived more than 10 days. The mean age of this group was 32.9 years, with a mean burn size of 36% of total body surface area; 83% were male. Of the 594 patients, 23.7% died and 38.7% had documented inhalation injury. The mean number of red blood cell transfusions received was 19.7, with a range of 0 to 201. Two hundred fourteen patients (36%) had major infectious complications, defined as pneumonia or invasive burn wound infection. A cross-tabulation of predicted mortality, number of transfusions, and infectious complications revealed a significant positive correlation between transfusion number and infectious complications in patients with predicted mortalities between 10 and 70%. Per cent total burn, patient age, presence of inhalation injury, and number of transfusions were identified by discriminant function analysis as significant variables (p less than 0.05) in discriminating between patients with and without infections (85% accuracy). Logistic regression analysis confirmed the above findings, showing a relationship between the number of transfusions received and infectious morbidity which was independent of age or burn size, but no significant relationship between number of transfusions and mortality.