The most detailed information on breeding of the Bahama Swallow is from Allen (1996). Nesting activity (prospecting for nest sites, carrying nest material to cavities) begins at the end of March or in early April. Bahama Swallows are cavity nesters; natural nesting sites are cavities in trees, but they also will use cavities associated with human habitations, including horizontal pipes, the housing around street lights, and nest boxes. Nesting in cavities in live trees has been reported, but all nests in trees observed by Allen were in dead snags. The mean height of the nest cavities was 8.8 m (range 6.0-11.4 m, SD ± 1.94, n = 18).
Only a single bird, presumably the female, contributes to nest construction. Nest materials are needles from Caribbean pine, grass, and the "needles" (fine, segmented twigs) of Casuarina spp., and usually are collected within 100 m of the nest. A wide variety of materials were incorporated into the nest lining, including flakes of pine bark and feathers.
The eggs are white and unmarked. The mean clutch size is 3.0 (range 2-4, SD ± 0.58, n = 13). The incubation period is approximately 15.8 days. The mean period to fledging is 22.7 days (range 22-25 days). In nests observed by Allen (1996), the hatching success was 87% and the nestling success was 81%, resulting in an overall success rate of 70%.