Systemic lupus erythematosus (SLE) is an autoimmune connective tisssue disease. Disregulation of proinflammatory cytokines' secrection plays a pivotal role in its etiopatogenesis. Most studies concerning serum levels of those cytokines were conducted in active SLE patients. To date, there are scarce date on proinflammatory cytokines' serum concentration in inactive SLE patients. The aim of the study was to evaluate serum level of IL-1beta, IL-6, IL-18 and TNF-alpha in inactive SLE patients. The study involved 25 SLE patients aged between 24-65 years (mean age 40.6 years) and 25 age- and sex-matched healthy volunteers. The activity of the disease was assesed by SLAM scale. Serum concentrations of IL-6 and IL18 were determined by ELISA while serum levels of TNF-alpha and IL-1beta were measured using chemiluminescensce assay. In all healthy volunteers and in 23 out of 25 SLE patients, serum level of IL-1beta was undetectable (< 5 pg/ml). Serum concentrations of IL-6, IL-18 and TNF-alpha were detectable in all SLE patients. In 9 out of 27 healthy subjects level of IL-18 was under detection limit. Serum levels of IL-6, IL-18 and TNF-alpha were significanly higher (p < 0.001) in SLE patients when compared to their concentrations in subjects from control group (3.45 pg/ml vs. 2.59 pg/ml for IL-6; 344.87 pg/ml vs. 50.31 pg/ml for IL-18; 7.72 pg/ml vs. 5.21 pg/ml for TNF-alpha, respectively). The evaluation of serum levels of proinflammatory cytokines may be a sensitive marker of disease activity which may be helpful in maintaining or withdrawing chronic therapy in SLE patients.