“The Unhappy Mistake” is a short story published in the late seventeenth century that has received little attention from critics. It has historically been attributed to Aphra Behn (1640–1689), but her authorship has been questioned by renowned critics like Janet Todd, Germaine Greer and Leah Orr. This article studies the translation produced by Jesus Serrano-Reyes (published in 2008 by Siruela) in order to draw attention to some of the translation strategies applied, showing (according to the principles of the Manipulation School and Polysystem Theory) the initial norm and type of equivalence. To this end textual binomials are analysed from the source and target texts, which consist of both key sentences, phrases, expressions, and even certain words. It also takes into account the style of some characters in Behn’s work, contrasting them with their depiction in the target text, specifically the style of the gentleman from Somertshire. Attention is also paid to the content of a political nature found in the story of Miles Hardman (whose flight from his country and domestic, and his return, constitute a metaphor for the exile of King Charles II and his Restoration), both in the original text and in the translation by Serrano-Reyes.