A retrospective review was performed on 2704 consecutive patients in Oslo in whom histologically or cytologically confirmed primary invasive breast carcinoma had been diagnosed between 1980 and 1989. The age-adjusted incidence rates were significantly higher in the city of Oslo compared with those of the whole country and remained unchanged during the study period. The percentage of patients who could be treated radically remained unchanged. Among the patients with radical treatment the distribution of pT category and stage was similar during the first and last years. The median delay (from onset of symptoms to start of treatment) of two months remained unchanged during the decade and was not related to patient's age, histological grade or tumour localization in the quadrants of the breast. With increasing duration of delay the number of patients not suitable for radical treatment increased. When considering all 2704 patients, the radicality of treatment, the patient's age and delay were correlated with tumour-specific survival and remained independent factors of tumour-specific survival in the multivariate analysis. The unchanged distribution of pT category and stage in the radically treated patients during the decade surveyed is most probably related to the lack of screening mammography in Norway.