Nests with eggs are reported from Costa Rica from late May to July (Marín and Siltes 1992), in Venezuela in July (Collins 1980), and in Ecuador in June (Marín and Stiles 1993). Additionally, Greeney (2004) found an empty but fresh nest of Spot-fronted Swift in Ecuador in late May.
Like other species of Cypseloides, Spot-fronted Swift nests on vertical rock faces in shaded areas near water (Collins 1980, Marín and Stiles 1992, 1993). The nest is more or less cup shaped, and made of moss and ferns, mixed with mud (Collins 1980, Marín and Stiles 1992, 1993) affixed to a vertical rock surface above a stream and near a 2.5m waterfall. Two nests in Venezuala had cup diameters of 55 mm and 56 mm (Collins 1980)..
The clutch size is one and the egg is white. The measurements of the egg that Collins found were 24 mm x 17.5mm, with a mass of 3.3 grams. This egg was found on 16 July 1976; he later found a very small, naked nestling on 4 August 1977. The hatch date for Ecuadorian birds was found to range from late April through early June (Marín and Stiles 1993), which is several months earlier than the Venezuelan birds.
Incubation period in Costa Rica 26-28 days; nestling period 65-70 days (Marín and Stiles 1993).