Background: Low Secure Mental Health Services provide care for highly disturbed psychiatric inpatients. Little is known about the provision of such services in the UK.

Aims: To perform the first UK wide survey developing a national data set for Low Secure Services.

Method: A cross-sectional census day postal survey design was employed.

Results: A total of 307 units were identified in the UK, this was comprised of 170 Psychiatric Intensive Care Units (PICUs) housing 1,242 patients and 137 Low Secure Units (LSUs) treating 1,583 patients. The survey achieved a 98% response rate. PICUs on average had more qualified staff and were more medically oriented than LSUs. PICUs offer a time limited, medically oriented treatment strategy with a higher number of qualified nursing staff then LSUs. Whereas, LSUs placed more of an emphasis on long-term therapeutic treatment and rehabilitation.

Conclusions: Although there were a variety of names, Low Secure Services were organised into two main categories of unit: the PICU and the LSU. These names should be adopted nation-wide as standard. There is need for a national strategy relating to the way PICUs and LSUs are developed.