Objective Our aim was to assess the palatine tonsil size with transcervical ultrasonography in healthy children and to analyze whether the palatine tonsil size is correlated with age, gender and body-mass index (BMI). Methods This series consisted of 680 healthy children (340 females, 340 males) who underwent transcervical ultrasonography for evaluation of palatine tonsil size. A total of seventeen age groups (range: 1–17 years) comprised of 40 children (20 females, 20 males) were constituted. Demographic data including gender, height, weight and BMI were noted. Correlation between baseline descriptive data and tonsil volume was investigated. Results The average age was 102.51 ± 59.24 months (range: 12 to 204) and body-mass index was 17.50–5.16 kg/m2 (min: 12.4-max:25.8). The average tonsil volume was 1819.5–2023.5 mm3 (min:601, max: 4007). The tonsil volume did not differ significantly between females and males (p = 0.108). However, there was a significant difference between tonsil volumes of various age groups (p < 0.001). Tonsil size seemed to be greater in parallel with advancement of age (p < 0.001) and increased BMI (p < 0.001). Conclusion Transcervical ultrasonography can be an accurate, safe, cheap, non-invasive and accessible measure for evaluation of the size of tonsils objectively. There were strongly positive correlations between age, BMI and palatine tonsil size in healthy children and variability with respect to descriptive characteristics must be considered during diagnostic procedures and preoperative evaluation. Advances in knowledge In our study, we suggest that transcervical ultrasonography can be an accurate, safe, cheap, non-invasive and accessible measure for evaluation of the size of tonsils. There were positive correlations between age, BMI and palatine tonsil size in healthy children.