The first observation of a metalloid site hyperfine field (hf) distribution in a ferromagnetic amorphous alloy is reported using a spin-echo NMR technique. The 31P nuclei in amorphous Fe75P15C10 show a hf distribution with a maximum at about 27 kOe. The sample was prepared with Fe enriched to 99.93% in 56Fe. A comparison of the NMR spectra on samples containing natural Fe and 56Fe also provides the 57Fe hf distribution whose peak value agrees with Mössbauer results. © 1977.