A portable platform with a retractable staircase, the portable platform having a platform frame. The frame is rectangular in shape and made up of four corner posts, front and rear panels, two midrails, and two top rails. The staircase pivots about a single pivot point situated at floor level on the platform, which also comprises a landing. The platform has two pivotable gates, one of which is situated at the front of the platform frame and the other of which is situated at the top of the staircase. An extension plate extends rearwardly from the rear panel of the platform at floor level and is configured to overlie a truck bed. Anchor legs extend downwardly from the extension plate and are configured to fit within existing apertures in the truck bed. The staircase is raised and lowered with a brake winch.