Three aspects of sex differences in reading achievement were investigated, based on data from school records and test results for first through fourth grade students in two parochial schools. The three aspects that were studied included (1) the relationship between sex-typed perceptions of reading and reading achievement, (2) changes in students' sex-typed perceptions of reading between grades one and four, and (3) those variables that discriminate between sex-appropriate and sex-inappropriate perceptions of reading. The results, inconsistent with those of past studies, suggested the possibility of the development of a new trend away from sex differences in reading achievement and from the sex-typing of reading as a feminine activity. In addition, the study showed that when reading was regarded as a sex-appropriate activity by members of both sexes, there were no significant sex differences in reading achievement. (RL)