Introduction: This article describes the incidence of first contacts with the psychiatric hospital services in the County of North Jutland (NJA) and the Municipality of Copenhagen (KK), Denmark, from 1 January 1994 to 31 December 2002., Materials and Methods: All persons age 18 and over living in NJA and KK in the period from 1 January 1994 to 31 December 2002 were identified through the Central Office of Civil Registration. First contacts with the psychiatric hospital services in the two areas were identified through the Danish Psychiatric Central Research Register., Results: Standardised incidence rates of psychiatric diagnoses were generally higher in KK than in NJA. Overall, for all diagnoses, there were 37 first contacts for men per 10,000 person-years in KK and 21 in NJA. For women, there were 40 contacts in KK and 26 in NJA. For diagnoses in the F0 group, the frequency was higher in NJA, with 6.7 first contacts per 10,000 person-years for men and 7.3 for women in NJA, compared with 4.5 for men and 3.9 for women in KK. For women with F6 diagnoses, the frequency was also higher in NJA than in KK: 2.7 first contacts per 10,000 person-years in NJA compared with 1.6 in NJA. Outpatient diagnosis of first-contact patients was more frequent in NJA than in KK (66% in NJA and 59% in KK)., Conclusion: The incidence of psychiatric diagnoses was higher in the urban area of KK than in the rural area of NJA. The higher incidence of F0 diagnoses in NJA may be due to differences in ways of registration. This might also explain why, in this investigation, more diagnoses after outpatient evaluation were made in NJA than in KK. We believe it is essential that continuing work on guidelines for registration of illness treatment in Denmark be performed.