The Hellshire Hills arguably contain the best example of old-growth dry forest remaining in the Caribbean. This area is home to many endemic and threatened species and unfortunately is also threatened by habitat degradation and large-scale development. Although biological surveys have been conducted in the region, detailed information for certain groups is lacking, particularly for terrestrial arthropods. In November 2013, 6 arachnologists spent 4 days in the Hellshire Hills using various methods to collect arachnids. We collected multiple species from 6 orders (excluding Acari, which we did not identify), including 1 species of Opiliones, 1 species of Solifugae, 1 species of Amblypygi, 3 species of Scorpiones, 4 species of Pseudoscorpiones, and 116 species of Araneae. Of these, we tentatively conclude (pending further analyses) that 2 genera and 33 species are new to science, and several others are new records for the island. Approximately 23 are endemic to Jamaica, and at least one, Selenops wilsoni, is known to be restricted to a very narrow range within the Hellshire Hills. Our study indicates that additional surveys would yield more species. Because many disparate taxa—plants, invertebrates, and reptiles—indicate high endemicity and species richness in the area, we recommend that human-mediated alteration of Hellshire should be avoided.