Background Previous research suggests that female violent offenders at risk of a prison sentence are more likely than their male counterparts to be assessed as having mental health problems of a nature or degree that would lead to a court requirement for hospital treatment. Aims/hypotheses To test the hypothesis that there is bias towards hospital disposal of female compared with male violent offenders with mental disorder. Methods In Sweden, the National Board of Forensic Medicine oversees all assessments of mental disorder for the criminal courts. Twenty‐six Board appointed forensic psychiatrists, psychologists and social workers each independently assessed six case vignettes for fit with criteria for ‘severe mental disorder’, a prerequisite for hospital disposal from court. Each gender neutral vignette described a person who had been convicted of serious assault and had a major mental disorder. A gender was then assigned to each offender randomly within a block design, thus varying between sets. Participants were blind to the main aim of the study and the gender variation. Results There was no significant association between gender of the person assessed and judgement that s/he had a ‘severe mental disorder’. An offender depicted as having mental retardation was more likely to be assessed as at high risk of criminal recidivism if portrayed as female, regardless of the sex, place of work or level of experience of the assessor. Conclusion We found no evidence of gender bias in determining appropriateness of a hospital disposal of an offender with mental disorder. The difference in assessment of recidivism according to sex of the patient was only in relation to mental retardation; further research would be needed to able to interpret this. As researchers in other countries have reported gender bias in disposals from court, our findings may provide support for a centralised forensic psychiatric assessment board and formal, on‐going training. Copyright © 2015 John Wiley & Sons, Ltd.