Ceftriaxone is a third-generation injectable cephalosporin. Like other third-generation cephalosporins, it has a broad spectrum of activity against bacterial species, including Gram-positive and Gram-negative bacteria, and is also stable against a wide range of β-lactamases. Like many third-generation cephalosporins, ceftriaxone is more expensive than earlier cephalosporins, but its long serum half-life (approximately 6-8 hours) means that it can be administered once daily, which can lead to cost savings. At the 11th European Congress of Clinical Microbiology and Infectious Diseases [Istanbul, Turkey; April 2001], 2 poster presentations showed that ceftriaxone once daily was more effective than less costly agents, and as effective as newer, more expensive agents, in the treatment of secondary peritonitis and biliary tract infections.1, 2