Antimicrobial streamlining is the practice of converting a broad-spectrum empirical regimen to therapy with either a single, narrow-spectrum parenteral agent or an oral agent as soon as possible. This practice results in many benefits for the patient and the hospital. When intravenous catheters can be removed early, the frequencies of catheter-associated bacteremias and phlebitis are reduced, thus making it possible to avoid incurring major costs. With the availability of newer oral agents with favorable pharmacokinetic, pharmacodynamic, and microbiological profiles, such as the fluoroquinolones, the macrolides/azalides, and the cephalosporins, the clinician has greater opportunity to employ streamlining tactics. The patient who is hospitalized with a lower respiratory tract infection (LRTI) often requires empirical antimicrobial therapy before the pathogen is identified. By day 3 of the hospital course, the pathogen is often known, the patient's condition may have stabilized, or both events may have occurred. At this point, streamlining is possible. At present, data suggest that rapid conversion from intravenous to oral antimicrobial therapy is safe and efficacious and should be considered for appropriate patients requiring hospitalization for LRTIs.