The spawning season of Gila trout, Salmo gilae Miller, in three streams in the Gila National Forest, New Mexico, began in early April at the lowest elevation and continued through June at the highest elevation. Water temperature and stream flow interacted to induce spawning; however, the former was more important. Spawning commenced at water temperatures near 8 C. Redds were normally in 6–15-cm deep water, about a quarter of the stream width from one bank and within 5 m of cover. The substrate was predominantly gravel and small pebble (0.2–3.8 cm). Spawning fish selected redd sites based on depth of water and substrate rather than on water velocity. Redds ranged in area from less than 0.1 m2to nearly 2.0 m2and averaged 3–4 cm in structural depth. Normally a single fish or a pair of fish occupied a redd, but occupancy by three to four fish was common. Most spawning activity occurred between 1300 and 1600 hours. Fry (15–20 mm long) emerged in 8 to 10 weeks and inhabited riffle areas. Absence of fry from pools occupied by adults indicated that cannibalism may occur.