Ceftriaxone is a new third-generation cephalosporin with excellent activity against many gram-negative, and reasonable activity against most gram-positive microorganisms. Clinical studies have demonstrated its efficacy and safety in patients with bacterial meningitis; respiratory tract, urinary tract, soft tissue, bone and joint infections; and gonorrhea. Ceftriaxone has been well tolerated except for diarrhea, which in most cases has not required a change in therapy. The long elimination half-life of ceftriaxone has allowed twice- and once-daily administration, the latter potentially resulting in substantial cost savings. Because of its documented efficacy, safety, and convenient dosing schedule, ceftriaxone may become the preferred third-generation cephalosporin for the treatment of a variety of serious infections.