The increasing epidemiological significance of infections caused by Mycoplasma, Chlamydia, and antibiotic-resistant microbes has been recently a pressing problem. This makes one to alter approaches to conventional antibacterial chemotherapy for bronchopulmonary infections. Differential approaches to treatment of community- and hospital-acquired pneumonias are based on the analysis of clinical conditions that are commonly characterized by the presence of definite pathogens. Macrolides, beta-lactamase antibiotics, third-fourth generation cephalosporins, fluoroquinolones, and carbapenemes have become common on a wider scale. Their pharmacodynamic parameters and postantibiotic effect are taken into account to a greater extent. Antibiotic use regimens, such as three-day azithromycin therapy, single daily aminoglycoside dose use, have also gained recognition. Three-stage therapy has been in use. This involves the parenteral use of a drug within 2-3 days at the first stage of treatment and oral antibacterial therapy follows when there is clinical improvement. The efficiency of this treatment is equal to that of parenteral therapy and side effects develop less frequently. It is essential that the stepwise treatment is more cost-effective, the cost of the antibacterial therapy reduces by 30-60%.