To assess skull bone thickness from birth to skeletal maturity at different sites to provide a reference for the correct selection of pin type and pin placement according to age. 270 children and adolescents (age: 0-17years) with a normal CT scan obtained at Emergency Department for other medical reasons were included. Skull thickness was measured on the axial plane CT scans at eight different sites of the vault: midline anterior (A) and posterior (P), right and left lateral (L), antero-lateral (AL), postero-lateral (PL). From birth to skeletal maturity, L thickness was increased significantly less (+ 58%) compared with AL (+ 205%), P (+ 233%), PL (+ 247%), and A (+ 269%) thickness (P < 0.01). At the end of growth, the thickest and thinnest points of the vault (absolute value) were found at the P and L measurement sites, respectively (P < 0.01). Children aged < 4years exhibited the highest variability in AL and PL skull bone thickness, with thickness < 3mm observed in 85% (64/75 patients) and 92% (69/75 patients) of cases, respectively. We recommend that the tip of the pin should not exceed 2-3mm in children aged < 4, and 4mm in children aged 4-6years, to decrease the risk of inner table perforation. After the age of 7years and 13years, standard-sized pin tips (5 and 6mm, respectively) may be safely used. Children aged < 4years show significant variability in skull thickness, and therefore a CT scan may be required for this particular age group.