Objective: To analyze the characteristics of referral from primary health care to mental health of patients with no diagnosable mental disorder., Methods: Consecutively and without exemptions, all persons attending for first-time consultation a mental health centre in the course of a year were clinically examined. We measured the incidence of conditions not attributable to a mental disorder using ICD-10 (Z codes). Information was collected on whose idea it was that they attended, and who, how and with what treatment they were referred. In addition, data about their social, demographic and clinical characteristics were collected., Results: Of the 1004 persons examined, 244 (24.4%) (95% CI, 21.6-27) did not meet the ICD-10 diagnosis criteria for mental disorders. They themselves or their family tended to request the Z codes (54.5%) (95% CI, 48.3-60.8]. Mental health referral was almost always through the PC doctor (95.5%) (95% CI, 92.1-97.7). Half the patients were already receiving drug therapy under their general practitioner before their visit and 20.9% (95% CI, 15.8-26) were referred as priority patients., Conclusions: Our study found that a large number of patients with no diagnosable mental disorder at the mental health centre, many of them with drug treatment prescribed, were referred. This places a question-mark over the function of primary care as a filter for these patients. The population s indiscriminate health care demand and the steady increase in treating mental health with drugs partially explain this phenomenon.