The aim of the study was to evaluate the efficacy and safety of low-dose, long-term cefadroxil prophylaxis in preventing recurrent urinary tract infections in children. A prospective, randomized trial in 33 children (32 female, 1 male) aged 2-14 years (mean 8.1+/-2.8) was conducted. Children with recurrent urinary tract infections were commenced to six-month prophylaxis with cefadroxil at the dosage of 12.5-15.0 mg/kg at bedtime administered every night (group I, n=15) or alternate night (group II, n=18). Escherichia coli was the most frequently isolated agent (90.9%), followed by Proteus mirabilis (3.0%) and Klebsiella oxytoca (3.0%) and Staphylococcus epidermidis (3.0%). Cefadroxil prophylaxis was effective in 80% of patients in group I and in 78% patients in group II. Reinfection occurred in 3/15 (20%) patients in-group I and in 4/18 (22.2%) patients in-group II (odds ratio--1.14; 95% confidence interval--0.16-8.3). The difference of reinfection rate between the groups was not significant (p=0.88). The rate of day- and night-time wetting in both groups before prophylaxis of urinary tract infections was high. It decreased significantly at the end of prophylactic treatment with cefadroxil (from 42.4% to 9.1% and from 39.4% to 6.1% respectively). Mild adverse reaction (nausea) was observed in 1/33 patient. In conclusion our study shows that cefadroxil is an effective, well-tolerated and safe agent in the urinary tract infections prophylaxis. Prophylaxis of recurrent urinary tract infections in children with cefadroxil on alternate night regimen might reduce the cost of the treatment.