Background: Inhaled corticosteroids have become the first-line medication for treatment of childhood asthma. Possible adverse effects, such as those on bone metabolism and urinary excretion of calcium are in the focus of interest. We investigated the influence of inhaled fluticasone on bone metabolism and renal excretion of calcium, sodium, and potassium in asthmatic children. Methods: Thirty asthmatic patients (mean age 12.24 +/- 2.75 years) treated with 200-250 mu g/day inhaled fluticasone were enrolled in the study. Prior to the initiation of therapy, as well as 12 weeks after following parameters were measured: serum sodium, potassium, calcium, phosphorus, creatinine, alkaline phosphatase, osteocalcin, intact parathyroid hormone levels, first-spot morning urine calcium/creatinine ratio, sodium/potassium ratio, and daily renal calcium excretion rate. Results: Serum electrolytes, alkaline phosphatase, parathyroid hormone, osteocalcin levels, as well as urinary calcium, sodium, and potassium excretion were within normal ranges. There was no statistical difference between values of those parameters prior and 12 weeks after initiation of the therapy. Conclusions: Treatment with 200-250 mu g/day inhaled fluticasone, in asthmatic children aged 9-16, during 12 weeks, did not affect serum osteocalcin level and renal excretion of calcium, sodium, and potassium.