7 species (see text) Isthmura is a genus of salamanders in the family Plethodontidae.

[1] The genus, which corresponds to the former "Pseudoeurycea bellii species group" and was first described as a subgenus of Pseudoeurycea, was raised to full generic level in 2015 in order to preserve Ixalotriton and Bolitoglossa while avoiding paraphyly of Pseudoeurycea.

[2][3] Isthmura are large to very large salamanders, and the largest plethodontid salamanders in the Neotropics.

They have robust, black bodies that usually have bold red, orange, or pink markings.

[2][4] They inhabit montane forests mostly above 2,000 m (6,600 ft), although Isthmura gigantea and Isthmura maxima have lower minimum altitude limits (respectively 1,000 and 750 m (3,280 and 2,460 ft)).