Objective – The analysis aims to identify the main patterns of Psychiatric Services provided by Local Health Unities in Lombardy. Setting – Data were collected by regional psychiatric information system in Lombardy in 1992 and 1993, concerning resources and activity. Design – We developed Cluster Analysis based on previously selected indicators of facilities, staff and activity. Multivariate analisys was performed in order to eliminate redundancy of information. Results – Five clusters corresponding to different patterns of psychiatric services were identified. In the first cluster services are particularly concerned with admissions (in private hospital, as well); other community activities can be considered quite dull both in composition of teams and variety of therapy. In the unities of the second cluster we pointed out low rates of community activities (mainly inside and hardly diversified) and admissions as well. The third cluster is distingueshed by an intensive community activity (both in quantity and variety) and turning to private sector for admissions, maybe because of a lack of rehabilitative facilities. Unities belonging to the fourth cluster have got many structures and a lot of staff dedicated to the hospital activity and to a intense (but little diversified) community activity. In the fifth cluster psychiatric services have got many rehabilitative facilities and community staff are well diversified; the considerable (but little diversified) community activity is carried outside. Conclusions – The community psychiatric services in Lombardy are not homogeneous and it is possible to identify five different and well definied patterns. The cluster analisys is useful to follow up the model, using information system data.