Background: Mental disorders are strongly associated with excess suicide risk, and successful treatment might prevent suicide. Since 1990, and particularly after 1998, there has been a substantial increase in mental health service resources in Norway. This study aimed to investigate whether these changes have had an impact on suicide mortality. Methods: We used Poisson regression analyses to assess the effect of changes in five mental health services variables on suicide mortality in five Norwegian health regions during the period 1990-2006. These variables included: number of man-labour years by all personnel, number of discharges, number of outpatient consultations, number of inpatient days, and number of hospital beds. Adjustments were made for sales of alcohol, sales of antidepressants, education, and unemployment. Results: In the period 1990-2006, we observed a total of 9480 suicides and the total suicide rate declined by 26%. None of the mental health services variables were significantly associated with female or male suicide mortality in the adjusted analyses (p > 0.05). Sales of antidepressants (adjusted Incidence Rate Ratio = 0.98; 95% CI = 0.97-1.00) and sales of alcohol (adjusted IRR = 1.41; 95% CI = 1.18-1.72) were significantly associated with female suicide mortality; education (adjusted IRR = 0.86; 95% CI = 0.79-0.94) and unemployment (adjusted IRR = 0.91; 95% CI = 0.85-0.97) were significantly associated with male suicide mortality. Conclusions: The adjusted analyses in the present study indicate that increased resources in Norwegian mental health services in the period 1990-2006 were statistically unrelated to suicide mortality.