Abstract: A mounting bracket assembly is disclosed which is suitable for mounting a radio or similar appliance either on a flat planar surface or over the drive shaft hump of a vehicle. The assembly includes a base adaptable to be secured to either a flat or curved surface and a U-shaped first support member releasably and adjustably secured to the base for pivotal movement about an axis normal to the plane of the base. The upstanding legs of the U-shaped first support member have through apertures therein and a pair of opposed L-shaped second support members are also provided. These second support members each have an elongate slot in their long legs so that they may be releasably and adjustably secured to the legs of the first support member for adjustment both along the longitudinal axis of the leg and about a horizontal axis. The remaining legs of the L-shaped second support members have elongate slots in them for adjustable attachment to the radio or other appliance.