The time of day of laying and the intervals between successive eggs in clutches of the Black-billed Cuckoo (Coccyzus erythropthalmus) have been incompletely documented. With observations bracketing the laying time of eggs, I determined that six eggs in four nests of the Black-billed Cuckoo were laid between 06:36 and 11:57 CST. Conspecific parasitism was recorded at one nest in which two eggs were laid on the same day, at 09:02 and 11:57; the second egg was likely the parasite's. Only one laying interval, of about 48 h, was determined accurately. There seems to be no best time for laying in parasitic cuckoos, because it may be dictated by host behavior.