Objective: The aim of this study was to examine the working of the 1945 Irish Mental Treatment Act in relation to compulsory admission and detention and to establish issues that will need to be addressed in imminent new legislation. Method: A 3 year retrospective study was carried out on all compulsory admissions to the Cavan/Monaghan Psychiatric Service using case note material. The circumstances surrounding application for compulsory admission in one year of the study period were further investigated by delivery of a schedule to Relative-Applicants. Results: The study revealed rates of compulsory admission equivalent to other Irish regions but much higher than neighbouring jurisdictions. There was no evidence of deliberate abuse of the act. Indications emerged of excessive and inappropriate recourse to certification by some relatives and General Practitioners. Excessive length of detained stay and lack of specific procedures for informing patients of their rights were evident. Conclusions: A new Mental Treatment Act will need to place much greater emphasis on patients' civil rights while facilitating access to treatment.