<i>Objective:</i> Thanatophoric dysplasia type 1 (TD 1) is typically a lethal dwarfism. We report our findings of fibroblast growth factor receptor 3 <i>(FGFR3)</i> mutations in Chinese cases of TD 1. <i>Methods:</i> Ten cases of TD 1 were identified prenatally by ultrasound. The <i>FGFR3</i> gene was analyzed using direct DNA sequencing of the selected regions (exons 7, 10, 15, and 19) previously reported to contain mutations for TD 1. <i>Results:</i> A heterozygous C742T (R248C) mutation was found in 9 of the 10 cases. The remaining case was negative for mutations involved in exons 7, 10, 15 and 19. <i>Conclusion:</i> The results suggest that the R248C mutation may serve as the primarily targeted one of the <i>FGFR3</i> gene for rapid molecular diagnosis of TD 1.