Poly(borazinylamine) has been investigated as a binder and as an in situ source material for boron and nitrogen in the frabrication of low volume fraction metal-matrix composites. The representative matrix metals employed in this investigation were aluminium, copper, iron, titanium, nickel and tungsten. The resulting metal-matrix composites contained metal borides and metal nitrides as the ceramic phases in 10.0 mol%, with the exception of copper which does not react with poly(borazinylamine). Although, the composites were prepared at ambient pressure, the aluminium- and titanium-based composites attained close to theoretical densities. The surface analysis of the composites by SEM and XPS showed the presence of a protective oxide layer composed of metal oxide and refractories.