Abstract: A draining threshold and door sill assembly has an elongated frame member forming an upwardly open channel and a sill that slopes away from the channel. A threshold cap is removably captured within the channel and protrudes slightly thereabove. An end cap is securely fastened to an end of the assembly and is formed with a drain trough that extends transversely beneath the end of the assembly. The drain trough has a first portion that at least partially underlies the end of the channel and extends to a mouth at the outside edge of the assembly. Rain water that seeps under the threshold cap and into the channel flows to the end of the channel and into the drain trough of the end cap, which directs the water beyond the outside edge of and away from the assembly. The threshold cap has no openings in the top thereof and is vertically adjustable in the channel by means of a set of threaded pedestals that depend from the bottom of the threshold cap and rest on the floor of the channel.