The addition of cerium in parts—per—million quantities has been shown to be effective in inhibiting the annealing embrittlement of melt—spun amorphous ribbons [1]. The effects of cerium doping on magnetic domain structures are reported in this paper. Domain structures have been observed using the Bitter colloid technique on the free surfaces of asquenched ribbons, as well as on both surfaces of ribbonswhich have been thinned by electropolishing. In the binary and quaternary alloys, the optimum (in terms of mechanical properties) cerium content gives ribbons which are apparently free of quenched—in stresses, since they lack the commonly observed “maze domains” which are found for both undoped and excessively doped ribbons. In contrast, the ternary alloy, which shows little decrease in annealing embrittlement versus doping, is free of maze domains in the as—quenched condition, with or without doping. The effect on the former two alloys is interpreted in terms of enhanced stress—relief during the quench.