Correct measurement of crown length is important for calculating the crown-implant ratio. The aim of this study was to compare the length of implant-supported crowns measured on digitized casts and intraoral radiographs. Crown lengths were studied in 50 patients with 86 implant-supported crowns in the posterior region. The mean length of implant-supported crowns was 9.83 ± 1.72 mm on three-dimensional models and 10.99 ± 1.91 mm on radiographs, which is a statistically significant difference (P .001). It can be concluded that a new gold standard for crown measurement should be defined.