Objectives: Preputial bacterial colonisation was investigated in preschool and primary school children with and without phimosis before the circumcision procedure. Method: The study group consisted of 32 boys admitted to our clinic consecutively between June 2003 and September 2003 for circumcision. The indication for surgery was religious belief in all patients. Immediately before the procedure, a swab was swept circumferentially once around the surface of the glans starting just proximal to the urethral meatus. In case of phimosis the same procedure was performed after complete retraction of the foreskin avoiding external contamination. The cultures were repeated in all patients after cleansing the glans and nearby preputium with polyvidon-iodine solution. Results: The mean age of the patients' was 6 (4-12) years. All 5 (100%) patients with phimosis had clinically significant (≥100,000 cfu/ml) uropathogenic bacterial colonisation. In 27 (84.3%) patients without phimosis culture reports revealed the absence of growth in 8 (29.6%) patients while 3 (11.1%) had Diphteroids and 1 (3.7%) had α-haemolytic Streptococci isolated from their preputial swabs which were accepted as harmless skin commensals. The rest of the boys (55.5%) had uropathogenic species in their preputium and all except 2 (7.4%) cases had counts exceeding 100,000 cfu/ml. The overall rates for individual species including any count were found as E. coli 3.1%, Klebsiella 18.8%, coagulase-negative Staphylococci 12.5% and Enterococcus 43.8%. Cleansing of perimeatal and periurethral region with 10% polyvidon-iodine solution markedly decreased the bacterial count in 80% of the patients with phimosis. Including eight patients with no growth before cleansing 88.9% of the patients in the non-phimosis group were free of preputial bacteria after cleansing with iodine solution. Conclusion: Significant preputial colonisation with uropathogens might still be present in preschool and primary school children. © Springer 2005.