This retrospective study aimed to explore possible gender bias in a population of non-psychotic but otherwise mentally disturbed violent defendants (The Danish Penal Code section 69) evaluated at the Clinic of Forensic Psychiatry in Copenhagen from 2007 to 2016 (N = 678). The results showed that female defendants in the total sample were 2.5 times more likely to be recommended for treatment than comparable male defendants, even when controlling for several confounders. However, when separating serious offences from less serious offences, the significant difference persisted only for the group of defendants charged with less serious violence. A logistic regression model including the gender of the defendant, the gender of the psychiatrist, and the interaction between these terms showed no significant interaction. Possible explanations concerning leniency, victimisation, and gender-specific criminogenic factors as well as diagnosis are discussed. However, interpreting real-life data is always complex and blinded case studies with psychiatrists evaluating the same case, but being randomized to different information concerning the gender of the defendant, are recommended to assess gender bias and explore the factors influencing such bias.