BACKGROUND: As many patients with severe mental illness (SMI) who have complex needs are difficult to engage, outreach mental health services are needed to engage them into treatment. The extent to which these services exist in large European cities is unknown. METHODS: Experts in 29 European countries were sent a structured questionnaire containing two case vignettes of difficult-to-engage patients (a first-episode psychosis patient and a homeless chronic schizophrenia patient). The type and quality of outpatient care was assessed and related to several national indices. RESULTS: The questionnaire was returned by experts from 22 countries (76%) representing 92% of the EU population. Six countries (21%) had a systematic method for detecting difficult-to-engage patients. The most important route whereby such patients entered the mental health system was through informal care; the most important reasons for entering it were the level of psychiatric symptoms, nuisance and violence. Assertive outreach was available in nine countries (41%), with coverage ranging from a few teams (sometimes for a specific target group) to most of the country. The case vignettes showed that outpatient care for these difficult-to-engage patients varied widely. In seven (30%) of the 22 countries, a hospital would take no action if such patients who had been admitted voluntarily discharged themselves prematurely. On a scale of 0-10, the experts' mean scores regarding the quality of outpatient care for patients with SMI in general were 5.2 (SD = 1.9) and 3.2 (SD = 2.2) in difficult-to-engage ones. Explorative analyses showed that the quality of outpatient care for difficult-to-engage patients was associated with gross national income and the number of psychiatrists per capita. CONCLUSIONS: Outpatient mental health services for difficult-to-engage SMI patients varied widely among European countries; experts judged their overall quality to be poor. It is now important to achieve consensus on a minimum European standard for the quality of care for such patients.