Septic pulmonary embolization occurs when an infected thrombus lodges in the pulmonary arterial tree. Pulmonary abscess, empyema, bronchopleural fistula, shock and death may follow. During the preantibiotic era, septic pulmonary embolization was a dread complication of septic thrombophlebitis occurring in the pelvis and after infections of the head and neck. More recently, the multiplicity of long term indwelling catheters has changed the epidemiologic aspect of this disease, pointing toward iatrogenic causes in many instances. The drug addict, however, remains the person at greatest risk of having septic pulmonary embolization develop. A clinical evaluation seeking drug abuse and related stigmata is extremely helpful in suggesting the proper cause, establishing the presence of right-sided endocarditis and directing appropriate therapy. Staphylococcus aureus is the most common offending organism in all patient populations except for the patient with thermal injury in which gram-negative organisms predominate. Early diagnosis and proper therapy, which includes high doses of parenteral antibiotics and control of the inciting septic focus in all instances, are prerequisites for a favorable outcome.