Crucisternum is a Neotropical genus of water scavenger beetle in the family Hydrophilidae represented by seven described species known from the Guiana Shield Region.

[2] It belongs in the subfamily Acidocerinae and contains seven described species from Brazil (Minas Gerais, Pará), French Guiana, Guyana, Suriname, and Venezuela.

[1][2] Small beetles (2.0–2.5 mm), smooth and shiny dorsally, orange-brown to dark brown in coloration, with long maxillary palps.

The most salient characteristic of the genus is the presence of a longitudinal carina on the prosternum, which is accompanied by a cruciform elevation on the mesoventrite.

[1][2] According to Girón and Short "All species of the genus are associated with forested streams, usually along margins that contain ample detritus".