Chronic lymphocytic leukemia (CLL) is a substantial problem of public health and oncology due to the increase of morbidity rates, frequent and refractory relapses, development of infectious complications, often leading to poor outcomes. The aim of the study was to determine the diagnostic features and evaluate the management outcomes of infectious complications in CLL. The study enrolled 82 patients with CLL aged 45 to 86 years (median age 66.2 years), who were treated and followed up at the Institute of Oncology of Moldova from 2000 to 2021. There were 47 men (57.3%), women – 35 (42.7%). The diagnosis was confirmed according to the IWCLL criteria based on the study of a complete blood count with the detection of lymphocytosis ≥ 5x10^9/l, myelograms with the bone marrow infiltration ≥30% and immunophenotyping. According to Binet Classification, 54 (65.9%) patients were diagnosed and followed up in stage A, and 28 (34.1%) patients – in stage B. The study was related to the out-patient and hospitalized care at the comprehensive cancer center. All immunophenotyped CLL cases proved to be CD20-positive. The study of the age distribution of CLL revealed the predominance of patients aged 60-79 years. The study of the disease evolution showed that out of 54 stage. A patients, 22 (40.8%) developed transformation of CLL into stage B in the period from 1 to 4 years. Transformation into stage C was revealed in 10 (35.7%) cases. The study of the frequency of infectious complications noted that in 36 (43.9%) cases there was at least one of their event. Bacterial infectious complications involved the respiratory system more commonly (29 patients, or 80.6%): acute pneumonia in 10 (27.8%), acute bronchitis in 7 (19.4%), exacerbation of chronic obstructive bronchitis in 11 (30.6%) and tuberculosis in 1 (2.8%) patient. Viral herpetic complications were diagnosed in 2 (5.6%) cases: each of them on the lips and genitals. The infectious complications with the affection of the other organs and systems were detected in 5 (13.8%) patients: in 3 (8.2%) – kidneys and urinary tract, in 2 (5.6%) – acute otitis. Over a period of 3–19 years, the fatal outcomes occurred in 16 (19.5%) patients: due to the infectious complications – in 6 (37.5%), as a result of CLL progression – in 5 (31.3%), because of the secondary tumors – in 4 (25.0%), and in one (6.2%) – due to the acute cerebro-vascular stroke. The overall survival rates after 3 and 5 years were 100% and 95.7% in stage A patients, and 84.8% and 55.4% – in stage B patients, respectively. The diagnosis of CLL was frequently proved in males aged 60-79 years due to the detection of the increased lymphocyte count in the complete blood count and bone marrow aspirate. Infectious complications may be considered as common evolution features and causes of death in CLL, especially in stage B.