Pre-admission forensic nursing assessment is a tradition that has no research evidence base, little documentary support and is an expensive drain on nursing resources from clinical environments. Such an expensive practice warrants some evaluation of the quality of these nursing assessments. This study assessed the quality of nursing risk assessments through comparison with the HCR-20, a well-established and widely validated violence risk assessment instrument. There was a high degree of correspondence between nurse assessments and the contents of the HCR-20. The results offer support for forensic nurses' abilities to develop effective measures and practices based upon nursing knowledge and experience where no formal evidence base previously existed.