The Cay Sal Bank in The Bahamas is one of the Caribbean region's most important areas for breeding seabirds, but the colonies previously lacked solid estimates. This paper describes results of four visits between 2010 and 2012. The Santaren Channel, used to transit to and from Cay Sal Bank, contained high numbers (6.1 ± 0.4 birds per km²) of seabirds. The Cay Say Bank has at least 117 detectable islands with 484 ha of land area; the most numerous colony was at Elbow Cay (23 ha). Audubon's Shearwaters (Puffinus lherminieri) were breeding at 97 pairs per ha (total: 2,200; 95% CI = 1,650–2,800 pairs), Sooty Terns (Onychoprion fuscatus) at 382 pairs per ha (total: 8,800; 95% CI = 6,900–10,700 pairs), Bridled Terns (Onychoprion anaethetus) at 38 pairs per km coastline (5,829 m coastline; total: 220; 95% CI = 145–295 pairs) and Brown Noddies (Anous stolidus) at 72 pairs per ha (total: 1,609; 95% CI = 1,070–2,250 pairs). The population of Audubon's Shearwaters is among the largest in the world while populations of the other species are regionally significant. Roughly 420 ha (87% of the available land) were visited; however, many of the smaller cays (43 islands with 30 ha of habitat) have still not been surveyed. Seabirds were present in low densities (0.3–20 total pairs per ha) on the other large islands, all of which contain populations of introduced black (Rattus rattus) or Norway (R. norveigicus) rats. These visits provide the first repeatable surveys of breeding seabirds at Cay Sal Bank.