Abstract: A multi-purpose adjustable doorjamb assembly includes at least three elongate members: a first side member, a second side member, and a cross member. Each elongate member has an inside longitudinal face opposite an outside longitudinal face. Each face has a longitudinal notch defined therein. The side members are attached to either ends of the cross member to form an open-sided rectangle. The assembly may also include at least three door stops. The jamb assembly may be used to accommodate swinging doors, bi-fold doors, or sliding doors. Finally, each elongate member may include a front longitudinal edge and a back longitudinal edge. Each edge has a longitudinal trim notch. The assembly further includes L-shaped trim members each having a mating leg for adjustably mating with the trim notch and a decorative leg. By using a trim member on both sides of an elongate member both narrow and wide walls can be accommodated.