This study aimed to evaluate the voiding characteristics of primary school children by using questionnaires and non-invasive diagnostic tools. The voiding characteristics of 212 healthy children in two primary schools were evaluated with ultrasound for bladder wall thickness (BWT) in association with the Pediatric Lower Urinary Tract Symptom Score (PLUTSS), familial questionnaire, uroflowmetry (UF) and urinalysis. Most of the children (70%) had achieved urinary and fecal continence between the ages of 18 months and 36 months. Twenty-five per cent of healthy children void fewer than four times or more than seven times per day. Ninety percent of children had a PLUTSS within normal ranges (< 9). Fifteen percent of patients had a uroflowmetric pattern other than bell-shaped. The peak and average flow rates were higher in girls. Enuresis nocturna was detected in 10% of children. None of the children had documented urinary tract infection. The average BWT from posterior wall at full bladder in healthy children was 1.1 mm. The anterior and posterior BWT measurements before and after micturition were found to be thicker in boys. Regarding the UF pattern, in post-voiding measurements in children with abnormal UF pattern, the bladder walls were thicker. Non-invasive tests in non-symptomatic children showed a range of variability, and these deviations should be kept in mind during the evaluation of voiding characteristics of a child. The symptom scoring system, with the high sensitivity and specificity rates it possesses, is one of the promising tools for this purpose.