Introduction: Secure extended care units (SECUs) are low-secure locked inpatient units. They are considered the most restrictive intervention within the continuum of mental health rehabilitation programmes for patients within non-forensic public mental health services. Limited information about psychosocial and forensic aspects of patients referred to such units is available. Aim: This study explored the psychosocial and forensic characteristics and predictors of acceptance in an Australian SECU programme over a 5-year period (2019–2023). Methods: A retrospective study design investigated 121 consecutive referrals. The 98 first-time patient referrals were included in the main analysis. Descriptive statistics were used with non-parametric comparisons (Chi-square and Fisher exact test where appropriate). Logistic regression was undertaken to assess the influence of covariates. Results: Referral from an inpatient mental health setting was the only predictor that influenced acceptance onto the SECU ( OR 3.168, 95% CI: [1.129, 8.913], p  = .029). More than four-fifths had a forensic history. Only 14 % had a history of youth offending, but 73% had a past conviction before referral. Sixty percent had a history of Family violence and two-thirds were on Bail. Services prioritised containment and abstinence, whereas patients sought skills development and employment. Patients had least contact with a Psychologist among all allied health disciplines before referral. Conclusions: The study provides evidence that the SECU is receiving patients with high forensic and psychosocial needs, which are unmet within community mental health programmes in the absence of medium and high-secure units. There is a need for a balanced approach between containment, rehabilitation, and community reintegration for this cohort.