The results of animal toxicology studies with cefodizime (CDZ) showed no reason for concern with respect to drug safety. Renal tolerance of CDZ proved to be better than that observed with other cephalosporins; furthermore, CDZ had no adverse effects on spermatogenesis, fertility or embryonic development. A total of 6,299 patients were treated with CDZ in clinical trials worldwide, while 1,225 patients received cefuroxime, cefotaxime, cefmenoxime or cefizoxime in comparative studies. The incidence of mortality in the repeated dose trials was 1.6% (CDZ) and 1.75% (comparators); the incidence of adverse drug reactions (ADRs) was 3.06% and 3.64%, respectively. ADRs were mostly of gastrointestinal or allergic nature. In no case was a causative relationship established between CDZ and the death of a patient. Any influence of CDZ on platelet count and function, plasma coagulation and vitamin K metabolism has been excluded. Cefodizime has a favorable risk/benefit ratio.