OBJECTIVE: To explore the variation in ovarian cancer survival in Denmark in the period 1978-2002 in relation to time since diagnosis, age at diagnosis, period of diagnosis, stage and histology. DESIGN: Register-based cohort study. SETTING: Denmark in the period 1978-2002. POPULATION: Using the nationwide Danish Cancer Registry, we included a total of 13,035 women diagnosed with invasive ovarian cancer in Denmark in the period 1978-2002. METHODS: Excess mortality risk analyses of five-year relative survival of ovarian cancer patients diagnosed in the period 1978-2002 with follow-up through 2006 were made based on data from the NORDCAN database. MAIN OUTCOME MEASURES: Five-year relative survival, excess mortality rate (ER) and relative excess mortality risk (RER) after an ovarian cancer diagnosis. RESULTS: The relative survival of Danish ovarian cancer patients slightly increased in the period 1978-2002. The ERs were highest in the first year following diagnosis, in particular in the first three months, and among older patients, even for localized and regional tumors. The pattern remained the same when stratified by histological subgroup. Older age at diagnosis, earlier period of diagnosis, more advanced stage at diagnosis and being diagnosed with undifferentiated carcinoma predicted poorer survival among Danish ovarian cancer patients diagnosed in the period 1978-2002. CONCLUSIONS: The survival of Danish ovarian cancer patients has slightly increased from 1978 through 2002. Despite this, the mortality rate of ovarian cancer in Denmark is still higher than in the other Nordic countries. Explanations for these differences are still to be identified.