A study was conducted to measure possible sex differences in phonological awareness and reading ability among children in early primary school. A subset of the "Dynamic Indicators of Basic Early Literacy Skills" (DIBELS) was administered to 140 children in kindergarten through to second grade (mean ages five to seven years). Independent variables were sex and grade level. Dependent variables were phoneme segmentation fluency; correct letter sound fluency and whole word reading fluency of non-words. Measurements on all dependent variables displayed a severe positive skew. Non-parametric tests revealed significant female superiority across all three dependent variables. The sex differences also increased between kindergarten and Grade 2.