A syndrome of sepsis arising on the third day after operation, trauma, or intensive care and caused by infection introduced through continuous intravenous devices with resulting acute thrombophlebitis has been documented in 54 patients. All patients had evidence of clinical sepsis associated with positive blood cultures. All had thrombophlebitis complicating a continuous intravenous infusion. Eighty-one percent had cultures of the intravenous device tip which grew the same organism as was recovered from the blood. The most frequent organisms cultured were Serratia (30%), Klebsiella (16%), Bacteroides (13%), and Staphylococcus (11%). Early recognition of the syndrome with removal of the continuous intravenous device, administration of appropriate antibiotics, and use of adequate supportive therapy produced the best results.