Magnetic inelastic neutron scattering studies have been performed on ribbon specimens of amorphous Fe83B16.5Si0.5and Fe20Ni60B19P1. The samples were prepared from isotopically enriched B to reduce the neutron absorption. The Curie temperatures for the two materials are 613 K and 410 K respectively, and the room temperature saturation magnetizations 4&pgr;Msare 16.0 kG and 5.1 kG. In the Fe20Ni60B19P1specimen, well‐defined spin waves were observed at room temperature for neutron wave‐vector transfers in the range q=0.06 A˚−1to q=0.20 A˚−1. After correcting for instrumental resolution, the data obeyed a quadratic dispersion law with spin stiffness D=80 meV‐A˚2. Spin waves in the Fe83B16.5Si0.5amorphous alloy exhibited a D=125 meV‐A˚2consistent with the higher Tcof this alloy.