Eotrogon stenorhynchus was an early trogon with a markedly narrower, more delicate bill than living trogons. It already possessed the characteristic heterodactyl foot, in which the second toe is turned backwards with the fourth, but its flight apparatus was less specialised for the short hovering manoeuvres used by some modern trogons.

It was almost certainly an arboreal bird. The slender bill suggests that its feeding differed from living broad billed trogons and may have involved taking small insects or other delicate prey, perhaps with some fruit. The exact diet is inferred from anatomy, but the combination of foot and bill provides unusually informative ecological evidence.