Syntomodrillia lissotropis is a species of sea snail, a marine gastropod mollusk in the family Drilliidae.

Original description, under the name P. (Mangilia) lissotropis, otherwise Mangilia lissotropis:[2] "The small, slender shell is somewhat bluntly tipped.

The protoconch is rather large, bullate, smooth, translucent, shining.

The remaining whorls show transverse, stout, shouldered ribs (on the body whorl eleven) becoming obsolete anteriorly, and succeeded by a few (four or five) revolving riblets at the anterior extreme of the siphonal canal.

"This marine species occurs in the Caribbean Sea and off Southern Brazil.