Performing a detailed dose measurement is important so as to keep radiation doses during computed tomography (CT) examinations as low as reasonably achievable. To estimate in detail the dose distribution during pediatric CT examination of the head, a flexible acrylic sheet roll CT dosimetry phantom (SRCT-P) with radiochromic film (RF) was developed. The dose distributions in the SRCT-P (diameters of 6 [premature baby], 10 [neonate], and 14 [infant] cm) were evaluated. The SRCT-Ps were made by rolling up flexible acrylic sheets (1.1 g/cm3). RFs were positioned every 5 mm along the radius at each SRCT-P, starting at 10 mm (center) and ending on the surface. The scanning parameters of the single detector CT were 120 kV, 250 mA, 1.0 sec/rot, a slice thickness of 5 mm, and a 1.0 beam pitch. The dose distributions along the z-axis at the center or on the surface showed a flat or wave pattern, respectively. When the mean surface dose at 10 cm diameter was taken as 100%, the mean surface doses at 6 or 14 cm diameters were 105 or 96%, respectively, and the mean center doses at 6, 10, and 14 cm were 109, 99, and 74%, respectively. The maximal dose area in the SRCT-P changed from the surface to the center with a decrease in the phantom diameter. The maximum-minimum doses and dose distribution of a CT examination can be measured separately by using the SRCT-P with RF.