In this article, we elucidate the way the gender gap in crime has changed in Sweden since the mid-19th century. The analysis is directed at theft offences and violent crime. The long historical perspective provides a background to our analysis that focuses on the period since the 1980s. Our principal data are comprised of the registered offending of different birth cohorts. Most of the findings from our study refute the hypothesis that the declining gender gap in crime is due to an increasing number of women committing offences. Instead, the most important driving forces in recent times have been a powerful decline in the number of men convicted of theft crime and a net-widening effect causing a rise in womens’ convictions for violence.