To observe the outcome of the fractured immature anterior permanent teeth after pulpotomy by X-ray measurement. A total of 31 (25 cases) fractured immature anterior permanent teeth after pulpotomy was reviewed. Radiographic measurements were performed on 12 cases with unilateral fractured central incisors and completely formed roots after pulpotomy and 100 (50 subjects) healthy maxillary central incisors. The roots development continued after pulpotomy, and the root length and periapical configuration were both similar to the healthy teeth, but some root canals became narrow or even nearly obturated at the root apex. There was no significant difference in root canal width between healthy right and left maxillary central incisors at the site of 1/4 [right: (0.67 +/- 0.14) mm, left: (0.66 +/- 0.12) mm, P > 0.05], 1/2 [right: (1.05 +/- 0.19) mm, left: (1.04 +/- 0.17) mm, P > 0.05], 3/4 [right: (1.78 +/- 0.34) mm, left: (1.76 +/- 0.30) mm, P > 0.05] of root, but the root canal width of the fractured incisors at the same site was significantly different from that of the contralateral healthy incisor, the 1/4 site pulpotomy: (0.70 +/- 0.23) mm, control: (0.99 +/- 0.17) mm, the 1/2 site pulpotomy: (1.16 +/- 0.24) mm, control: (1.51 +/- 0.25) mm; the 3/4 site pulpotomy: (1.96 +/- 0.34) mm, control: (2.24 +/- 0.36) mm. There was a tendency that the root canals of fractured teeth after pulpotomy became narrowed and obturated. It should not be followed up for too long to perform root canal treatment when roots completely formed.