Learned helplessness is a variable which has commonly been considered in research on sex-related differences in mathematics achievement. In this study, learned helplessness has been defined in terms of a debilitating or facilitating response resulting from failure on mathematical word problems. The construct has been called Performance Following Failure (PFF) to distinguish it from attributional definitions of learned helplessness. Algebra students (N=124) were given an ability measure, a mathematics achievement measure, and a PFF measure. Results showed that: (1) females (N=61) scored significantly lower than males (N=63) on the PFF measure, that is, they were more learned helpless; and (2) PFF was related to mathematics achievement for females but not for males. These findings indicated that a sex-related difference in PFF may be stronger than would have been expected from the related literature. It is suggested that PFF is a variable which needs to be considered when discussing sex-related differences in variables related to mathematics achievement. (Author/JN)