The aim of this study was to evaluate an intervention programme for people with severe mental illness that targets the reduction in compulsory psychiatric admissions. In the current study, we examine the feasibility of retaining patients in this programme and compare outcomes over the first 12 months to those after treatment as usual (TAU). Study participants were recruited in four psychiatric hospitals in the Canton of Zurich, Switzerland. Patients were eligible if they had at least one compulsory admission during the past 24 months. Participants were assigned at random to the intervention or to the TAU group. The intervention programme consists of individualised psycho-education focusing on behaviours prior to illness-related crisis, crisis cards and, after discharge from the psychiatric hospital, a 24-month preventive monitoring. In total, 238 (of 756 approached) inpatients were included in the trial. After 12 months, 80 (67.2 %) in the intervention group and 102 (85.7 %) in the TAU group were still participating in the trial. Of these, 22.5 % in the intervention group (35.3 % TAU) had been compulsorily readmitted to psychiatry; results suggest a significantly lower number of compulsory readmissions per patient (0.3 intervention; 0.7 TAU). Dropouts are characterised by younger age and unemployment. This interim analysis suggests beneficial effects of this intervention for targeted psychiatric patients.