To provide a thermosetting resin composition for a printed wiring board that enhances adhesion to a copper foil without reducing the compounded amount of a filler for ensuring flame retardancy, a prepreg and a laminated plate for printed wiring boards.

The thermosetting resin composition for printed wiring boards comprises 100 pts.wt. of the total amount of organic solid components comprised of components (a) 35-75 pts.wt. of a compound bearing a dihydrobenzoxazine ring in the molecule, (b) 10-25 pts.wt. of a polycondensate of a phenolic compound, a triazine ring-bearing compound and an aldehyde compound, and (c) 10-45 pts.wt. of an epoxy resin, and comprises (d) 5-35 pts.wt. of a condensed phosphate ester and (e) 1.0-10 pts.wt. of a sulfur compound, and further comprises (f) 30-100 pts.wt., based on 100 pts.wt. of the total amount of the solid content of (a), (b), (c), (d) and (e), of an inorganic filler, with the proviso that the halogen content in all the materials used is at most 0.1 wt.%.