The structural and magnetic properties of Fe62Co9.5Gd3.5Si10B15 alloy in as-spun and annealed states have been investigated. The presence of a nanocrystalline (Fe,Co)3Gd phase together with an amorphous phase in the as-spun ribbon was recognized. The primary crystallization of the amorphous phase occurred at 928 K. In spite of the presence of (Fe, Co)3Gd nanoparticles, the materials in the as-spun state exhibited a low coercivity of 2.74 A m-1 and the coercivity further reduced to 2.45 A m-1 after annealing at 773 K. The Curie temperature also increased with increasing annealing temperature. Excellent ac magnetic properties were also observed in the annealed specimen. The results indicate that the materials may be used for high frequency application. The good soft magnetic nature of the materials significantly deteriorated after annealing at temperatures above 823 K because of the precipitation of highly anisotropic B-rich phases.