Background.Previous reports on the outcome of services for offenders with developmental disabilities have found recidivism rates of between 40% and 70% with an elevated prevalence of sex offending, fire‐raising, and aggression. Studies have also reported that female offending rates in the intellectual disability population are broadly similar to those found in mainstream populations. All reports have been conducted on in‐patient or prison samples. The present report is of a community forensic intellectual disability service.Method.Two male cohorts of sex offenders (N= 121) and other types of offenders (N= 105) and female offenders (N= 21) are studied and compared. Data is reported on characteristics of the cohort, problems identified at referral, criminal justice disposal trends, index offences at time of referral, reoffending rates of up to 12 years after index offence, patterns of referral in the first 6 and second 6 years of the study period and the extent of harm reduction.Results.There were no differences between the groups on IQ and the sex offender cohort tended to be older. Female offenders had higher rates of mental illness although rates for the male cohorts were generally high at around 32%. The sex offending cohort had fewer problems with anger and aggression and alcohol abuse but a higher level of daily living problems and relationship problems. Female offenders had high rates of all problems studied except daily living problems. Unlike certain previous studies, sex offences predominated in the sex offender cohort while other types of offences predominated in the other two cohorts. Average age was lower for more recent referrals. Among recidivists only, a considerable amount of harm reduction was recorded.Conclusions.Fire raising and offences against children are not overly represented when compared with mainstream offenders. When compared with previous studies, it appears that a community forensic intellectual disability service may have an impact in reducing the number of offences committed over a 12 year follow up per