Background: Many hospitalized patients with community acquired pneumoniae can be switched early in the course of therapy from intravenous to oral antibiotics, when there are subjective and objective indicators of improvement. This modality of treatment is called "switch therapy". Aim: To compare sequential therapy using an oral third generation cephalosporin, with conventional therapy using intravenous ceftriazone in community acquired pneumonia. Patients and methods: Forty patients admitted due to community acquired pneumonia, initially treated with ceftriazone 1 g/day iv and that showed clinical improvement after three days of therapy, were studied. They were randomly assigned to continue intravenous therapy with ceftriazone for a total of 10 days or switched to ceftibuten 400 mg od for seven days. Results: Twenty one patients continued iv treatment and 19 were switched to ceftibuten. There were no differences between both groups in terms of clinical cure, radiological improvement or normalisation of white blood cell count. Conclusions: Patients with community acquired pneumonia that have a good initial response to intravenous antimicrobials, can be safely switched to oral therapy. This therapy will shorten hospital stay and thereby treatment costs