Acute lymphoblastic leukemia is the most common type of childhood cancer, accounting for about 23% of all cancers diagnosed in this age group. The last stage of radical treatment is remission maintenance, during which hospitalization is not necessary. The lesions occurring in the oral cavity caused by medications and chemotherapy may also be directly related to hematological and systemic disorders. The aim of this study was to examine the levels of selected pro- and anti-inflammatory cytokines in saliva and serum of both patients undergoing remission maintenance and those after the cessation of therapy who reported to the hematology clinic of the Pediatric University Hospital in Lublin. The results were later analyzed in relation to the frequency of oral lesions and subjective intensity of oral complaints. The study revealed significant differences in salivary and serum concentrations of TNF- and

IL-10 between test and control groups. Oral lesions were more frequent in patients receiving therapy compared to the control group. Subjective afflictions described by the Visual Analog Scale (VAS) mean values were highest in the control group.