Objective: This pilot study in a specialist mental health crisis assessment and treatment setting compared patients' outcomes and level of satisfaction in nurse-initiated care and in treatment as usual. Methods: Initially, the nurse's decision making in 51 cases was evaluated and rated by a psychiatrist (February 2005 to May 2005). A quasi-experimental design was then used to compare nurse-initiated care (experimental group) with treatment as usual (control group) in terms of consumer and caregiver satisfaction and outcome. A total of 103 clients of a mental health crisis assessment and treatment team were randomly assigned to the two groups. Differences were determined by comparing the Health of the Nation Outcomes Scale (HoNOS) scores and consumer and caregiver satisfaction surveys. Data were collected over a 12-month period (September 2005 to September 2006). The nurse who initiated treatment in the experimental group was a nurse practitioner candidate, meaning that the nurse had not yet completed the requirements to be endorsed as a nurse practitioner but was operating as a nurse practitioner but under the direct supervision of a consultant psychiatrist. Results: There were no significant differences between nurse-initiated care and treatment as usual in terms of HoNOS scores or consumer and caregiver satisfaction. This was not due to clinical or demographic differences between the two groups nor to an inadequate sample size. Overall, the nurse was found to follow best or acceptable clinical practices. Conclusions: The findings indicate that the nurse practitioner role can potentially initiate safe and effective mental health care and treatment that is as satisfying as that initiated by a physician. Additional, larger-scale research is required to determine the generalizability of these findings.