Fiber-containing polymethyl methacrylate (PMMA) prepregs are described that include a first and second plurality of fibers. The second plurality of fibers is made from a different material than the first plurality of fibers. The PMMA prepregs also contain a polymerized resin that includes polymethyl methacrylate that has been formed from a reactive resin composition that includes methyl methacrylate. Methods of making fiber-containing PMMA prepregs are also described.