Infection is a significant cause of morbidity and death in patients with chronic lymphocytic leukemia (CLL). Increased infectious events may arise from the multiple courses of immunosuppressive therapy and progressive deterioration of a patient's immune system over the course of disease. The humanized, anti-CD52 monoclonal antibody alemtuzumab (Campath or Campath-1H) has shown notable activity for both untreated and fludarabine-refractory CLL. The antibody not only targets malignant cells but also affects normal, healthy immune cells. The cumulative effects of the malignancy and successive courses of treatments adversely impinge on a patient's defense response to certain bacterial, fungal, and viral infections. In this review article, we provide an overview of common infectious events associated with alemtuzumab therapy in CLL. We also discuss recommendations for effectively monitoring and managing infections in CLL patients.