We identified and described Cortiella yatungense, a new species of Cortiella (Apiaceae) from Xizang, China. This species can be distinguished from other members of this genus (C. hookeri, C. caespitosa, C. lamondiana, and C. cortioides) by fewer umbels (3–6), thinner and longer pedicels than the leaves, ovate to suborbicular fruits, and mericarp without vittae. Molecular phylogenetic analyses based on the internal transcribed space (ITS) region and two chloroplast DNA intron sequences (rpl16 and rps16) showed that C. yatungense was sister to C. hookeri with strong support. Thus, both morphological and phylogenetic evidence suggested that C. yatungense is a distinct species of Cortiella. A comprehensive description of C. yatungense along with morphological characteristics and habitat are provided.