86 spp. were collected during July 1988 in Guanacaste National Park, north-west Costa Rica. Argia cuprea Hagen, A. eliptica Selys, Philogenia peacocki Brooks, Palaemnema baltodanoi Brooks, Epigomphus echeverrii Brooks and Phyllogomphoides burgosi Brooks had not previously been recorded from Costa Rica. The distributions of the Odonata species within the Park are briefly discussed.