An adjustable scaffolding tunnel assembly. The assembly includes a first pair of posts connected on upper and lower portions thereof to a second pair of posts via grooved members. A first cross beam is positioned between the first pair of posts, and a second cross beam is positioned between the second pair of posts. A plurality of support beams is disposed between the first and second cross beams. The first and second pairs of posts are vertically adjustable, and the first and second cross beams and the support beams are laterally adjustable. In this manner, a height and a width of the assembly are individually adjustable. The adjustable scaffolding tunnel assembly can hold one or more isolation members, such as wood or drywall, to isolate an interior of the assembly from an exterior of the assembly.