BACKGROUNDS. Lyme borreliosis is a disease which affects many organ systems. It is tran­smitted by ticks and caused by the bacteria Borrelia burgdorferi sensu lato. Borrelial lymphocy­toma is a clinical sign of early localized Lyme borreliosis in children. METHODS. The clinical study was retrospective. It included 45 patients who were treated at the Department of Infectious Diseases, University Medical Centre, Ljubljana, Slovenia, from 1 January 2001 to 31 Decem­ber 2007. The diagnosis of borrelial lymphocytoma was based on the Centers for Disease Control and Prevention criteria for the diagnosis of Lyme borreliosis in children. The basic demograp­hic data and data about the course of the disease were collected using a questionnaire. A group of 42 patients who fulfilled the inclusion criteria was enrolled and included 18 females and 24 males. RESULTS. The medium age of the patients was 5 years. 19% of the patients had had a tick bite. 97.6% of the patients had solitary borrelial vlymphocytoma. B. burgdorferi sen­su stricto was isolated in one patient’s blood. One of the female patients had borrelial lymphocy­toma, erythema migrans and meningitis simultaneously. Three patients with borrelial lymphocytoma were hospitalized. CONCLUSIONS. In children, borrelial lymphocytoma appears seasonally, mostly in June. In the majority of children, it appears on the earlobe. For most chil­dren, it involves an easy initial disease, but more than half of the cases have associated local and/or general symptoms. The diagnosis of Lyme borreliosis is confirmed in only one third of children with borrelial lymphocytoma. More than a third of children also have specific antibodies against the borrelias causing Lyme borreliosis, but in the blood of children with borrelial lymphocytoma the presence of the latter is very rare.