OBJECTIVE: To study the change in risk of suicide among patients with schizophrenia and related disorders. DESIGN: Nested case-control design with linked data. SETTING: 4 longitudinal Danish registers. PARTICIPANTS: 18,744 people aged up to 75 years who committed suicide in 1981-97 individually matched with 20 controls. RESULTS: Over the time studied the reduction in suicide rate among patients with schizophrenia and schizophrenia spectrum disorder was similar to that seen in the general population (incidence rate ratio 1.00, 95% confidence interval 0.98 to 1.03). The reduction among patients with other psychosis in the schizophrenia spectrum was faster than the reduction seen in the general population. Among people admitted to hospital with schizophrenia the risk of suicide was highest in the first year after first admission, and the excess risk was largest in the younger age groups-that is, the risk decreased per year for every additional year of age. CONCLUSION: The suicide rate among patients with a diagnosis of schizophrenia and related disorders has fallen. This may be due to better psychiatric treatment, reduced access to means of suicide, or improvements in treatment after suicide attempts.