Background/aims: The aim of this study is to figure out defecation features, constipation frequency, reasons and factors effecting on functional constipation in 0-6 years old children. Material and Methods: This descriptive study had been carried out in Gazi University School of Medicine Pediatric polyclinics between February-June 2007 and 1018 children aged 0-6 years were included. The study comprises data about defecation pattern and prevalence of constipation. Children were divided into five groups according to the age. Their parents were asked to complete a structured questionnaire. Physical examinations, stool frequency according to the age, feeding patterns, age and gender distributions, major complaints and associated factors were all investigated. Results: Among 1018 children there were 526 (51.7%) boys and 492 (48.3%) girls. One hundred ninety five (88.2%) infants were exclusively breastfed, 42 children (17.8%) were getting additional feeding in 0-6 months age group. Forty-eight of 1018 children (4.7%) were diagnosed as constipated. Twenty-eight (58.3%) were male and 20(41.7%) were female. Parents of the constipated children defined the major complaints with defecation as discomfort (33%), pain (25%), seldom defecation (21%), hard stools (17%) and rectal bleeding (4%). Eighteen parents (37.5%) thought that constipation is related to dietary type. Refraining from school toilet was defined by seven parents (14.6%). Conclusion: Constipation may predict serious organic problems in newborns; however organic problems are not encountered in 95% of bigger children. These cases are described as functional constipation. Dietary factors and refraining from school toilets have to be considered during treatment.