From 2015 to 2022, I studied nest box use, sex ratios, reproductive success, and morphometrics of the Western Screech-Owl (Megascops kennicottii) and Whiskered Screech-Owl (M. trichopsis) in southeastern Arizona. The Whiskered Screech-Owl in particular is at the extreme northern end of its distribution in the southwestern United States, with past research suggesting that it does not readily use nest boxes. Both screech-owls occurred in the study area in unknown densities but nest box use was higher with the Whiskered Screech-Owl. The Whiskered Screech-Owl nestling sex ratio varied but averaged about equal, with the mean number of male to female nestlings per brood being 1.11M:1.22F. Nest success was high for both species. Recapture data suggest that juveniles disperse outside of the study area and adults maintain site fidelity. Fourteen adult Whiskered Screech-Owls and 23 nestlings along with 9 adult Western Screech-Owls and 7 nestlings were banded over the course of this study.