Aphra Behn’s dramatic outputs are recognized for their diversity and responsiveness to trends in Restoration drama. A stylometric approach is used to investigate the linguistic dimension of Behn’s dramatic style, with a particular focus on evidence of chronological change. Quantitative analysis (most frequent words, function words, zeta) suggests that Behn’s drama falls into three periods. A qualitative analysis indicates that the periodization may reflect a change in the construction of Behn’s dramatic worlds, from an abstract psychological focus to a more grounded, interactive and social representation. The study considers the problematic dating of Behn’s tragi-comedy The Young King. Although critical opinion holds that this play was the first that Behn wrote (i.e. pre-1670), the stylometric analysis suggests that Behn heavily revised, or, indeed, penned, the drama in the mid-to-late 1670s, mid-way through her writing career. The paper demonstrates the potential for stylochronometric techniques to complement other linguistic approaches to style, and enhance our understanding of how literary writing evolves.