The aim of this study was to establish the prevalence of nocturnal incontinence (NI) in 6-to-7-year-old children from eastern Croatia, to determine the factors associated with NI and to evaluate parental perception of the problem. From May to September 2004, the parents of 3,011 children were asked to complete an anonymous validated questionnaire. The overall prevalence of reported NI was 1.2% (35/3011). All of the cases were cases of secondary NI. NI was significantly more frequent in boys than in girls. Family history of enuresis was present in 68.6% (24/35) of enuretic children. Only 17.1% (6/35) of parents expressed some concern about the effect of the researched problem on their child's future development. The frequency of NI in this study group is much lower than that reported in other European countries. The reason for this is still not known, although parental perception of this problem is certainly a significant factor. Further investigations are needed.