Girls are more likely to outperform boys in the development of writing skills. This study considered gender differences in language and working memory skills as a possible explanation for the differential rates of progress. Sixty-seven children (31 males and 36 females) (Mi age 57.30 months) participated. Qualitative differences in writing progress were examined using a writing assessment scale from the Early Years Foundation Stage Profile (EYFSP). Quantitative measures of writing: number of words, diversity of words, number of phrases/sentences and grammatical complexity of the phrases/sentences were also analysed. The children were also assessed on tasks measuring their language production and comprehension skills and the visuo-spatial, phonological, and central executive components of working memory. The results indlicated that the boys were more likely to perform significantly less well than the girls on all measures of writing except the grammatical complexity of sentences. Initially, no significant differences were found on any of the measures of language ability. Further, no significant differences were found between the genders on the capacity and efficiency of their working memory functioning. However, hierarchical regressions revealed that the individual differences in gender and language ability, more specifically spoken language comprehension, predicted performance on the EYFSP writing scale. This finding accords well with the literature that suggests that language skills can mediate the variance in boys' and girls' writing ability.