A prospective, double-blind, randomized study of hospitalized patients with skin and skin structure infections was conducted to compare orally administered ciprofloxacin and conventional intravenous cefotaxime therapy. Fifty-six patients, predominantly elderly women, were randomly assigned to receive either ciprofloxacin (24 patients, 25 infected sites) or cefotaxime (32 patients, 36 sites). Patients in the ciprofloxacin group received 750 mg of orally administered ciprofloxacin every 12 hours plus a placebo infusion while the other group received 2.0 g of cefotaxime intravenously every eight hours plus a placebo tablet every 12 hours. The average duration of treatment was seven to 10 days, with a maximum of 21 days. Clinical response per infected site in the ciprofloxacin group was as follows: resolution in 88 percent, improvement in 8 percent, and failure in 4 percent. In the cefotaxime group, there was resolution in 69 percent, improvement in 25 percent and failure in 6 percent. Bacteriologic response per site in the ciprofloxacin group was eradication in 88 percent and persistence in 12 percent. With cefotaxime there was 69 percent eradication, 3 percent marked reduction, 6 percent recurrence, and 22 percent persistence. Clinical and bacteriologic responses were combined using an algorithm to derive a cure rate, which was 91 percent for ciprofloxacin and 61 percent for cefotaxime (p = 0.0214).