There is very little information on the reproductive biology of Sickle-winged Nightjar. Eggs are reported from Brazil in November, and recently fledged young from December; specimens with enlarged gonads are reported from August-October (Collar et al. 1992). Presumably Sickle-winged Nightjar makes no nest, but lays the eggs directly on the ground. The eggs are pinkish buff or pale buffish, are spotted and scrawled with brown and gray, and measure 23.2-31.4 x 18.2-22.8 mm (Cleere 1998).