This article describes the results of a survey conducted among nurses who work in psychiatric care. Within the experimental condition of a randomized controlled trial, they executed an intervention protocol to prevent psychotic relapses among patients with schizophrenia. The central objective of this protocol was early recognition of the warning signs of psychosis and timely performance of actions intended to re-establish the equilibrium of the patient. The nurses were asked about the execution of the intervention, their experiences with it, and their evaluation. The nurses actually did execute the protocol in large measure and also made use of opportunities to tailor it to the individual patient. For the most part, the nurses judged that the intervention protocol contributed significantly to the treatment of the patient. The survey also revealed a number of difficulties in the execution of the protocol that deserve attention in the future.