Community-acquired pneumonia (CAP), or pneumonia acquired outside the hospital, is a very common disease caused by numerous microorganisms with various clinical presentations, disease severity and outcome. CAP is associated with significant morbidity and mortality in affected population and rising costs of medical treatment worldwide. Uniform and improved clinical approach and treatment of adult patients with CAP is advocated in many guidelines developed by various institutions and professional associations. All current guidelines for the treatment of CAP are based on clinical ­diagnosis of pneumonia confirmed by chest radiography and empirical choice of antibiotics. As other well-known guidelines (American, European, British), the Croatian guidelines are trying to rationalize clinical approach based on the assessment of disease severity, patient age, comorbidities, risk factors and epidemiological data. Depending on disease severity, diagnostic and therapeutic procedures are prescribed according to the site of care for CAP patients: outpatient setting, hospital wards or the intensive care unit. Antibiotic treatment of pneumonia should be initiated immediately, or within four hours after establishing the clinical diagnosis. Parenteral administration of antibiotics can be switched to oral usually 48 to 96 hours from the start of treatment, even in patients with severe clinical presentation of disease if all criteria are met. Vaccination against influenza and pneumococcal disease is recommended for all high-risk persons. Expert representatives of five professional societies of the Croatian Medical Association and Croatian Thoracic Society and the Reference Center for Diagnosis and Treatment of Infectious Diseases of the Croatian Ministry of Health participated in the preparation of these guidelines. They are designed for general practitioners and specialists from different medical disciplines who treat patients with pneumonia in outpatient or hospital setting.