A study examined the relationship between sex differences and the development of reading proficiency, specifically investigating if sex differences related to achievement on measures of silent reading comprehension, sight vocabulary, recognition of vocabulary in context, and use of structural analysis in word recognition taken separately or in combination. The subjects, 84 male and 79 female second-grade students who were reading at or above the 1.5 grade level, were tested using a series of separate Metropolitan Achievement Tests. Results indicated no significant differences in the reading scores of boys and girls. These results support previous findings of Steiner, Steinen, and Newman (1981) and represent a significant departure from the literature in which differences favoring females have been reported for the past several decades. (A table of data is included and references are attached.) (NH)