A new species of antipatharian coral (Anthozoa: Antipatharia) is described from the Pacific coast of Costa Rica. Lillipathes ritamariae, new species, forms large, multi-branched, flabellate colonies that reach a height of 60 cm or more. The genus Lillipathes is characterized by pinnules in four rows and arranged in bilateral alternating pairs. In L. ritamariae, the pinnules occur in only two rows in portions of the corallum; however, the characteristic Lillipathes pinnulation pattern is common enough to support assigning this species to this genus. The species can be distinguished from its cogeners by its very short pinnules (mostly 1–1.5 cm in length) and the development of many of the lateral pinnules into pinnulated branches. In contrast, in L. wingi, the pinnules are up to 5 cm long and only a few in the colony develop into branches. In L. quadribrachiata, the pinnules are up to about 3 cm long, and in Lillipathes lilliei, the pinnules are more than 10 cm in length, and only a small number develop into branches.