In the last decade, preventive detention—especially that relating to sexual offenders— has gained relevance for the German legal system. However, data are lacking concerning the inmates and the modus operandi of the psychiatric experts. Court orders and psychiatric statements of 114 offenders with orders of preventive detention were examined, 57 of whom were incarcerated because of sexual offences. Sexual offenders mostly show antisocial personality traits or even disorders, with a history of poly-trophic delinquency. In only four cases, the diagnosis of a sexual disorder was given. The analysis showed a high rate of psychiatric expert testimonies' lacking basic information, with incomplete assessment of sexual history. None of the experts used standardized prognostic instruments, meaning that most of the risk factors included in the Sexual Violence Risk—20 and the Static-99 were not considered. Further work needs to be done to improve the quality of psychiatric statements concerning sexual offenders.