In order to assess the benefits and limitations of pathology databases to cancer registries, computerised pathology records of malignant neoplasms diagnosed during 1992 were obtained for a defined area of Scotland for which pathology data were not routinely being used for cancer registration. Apparently 'missed' cancer registrations were identified by computerised probability matching with cancer registration records and their eligibility for registration was determined by reference to medical records, or when these were unavailable, by reference to the text of the original pathology report in conjunction with the local Community Health Index (to establish residency at the time of diagnosis). Misclassifications of site or incidence year were not regarded as 'missed' cases. Of 218 apparently 'missed' cancer registrations identified from computerised pathology records, 133 (5.7% of the revised total number of registrations for the study area in 1992) should have been registered. A further 14 cases were already registered but with misclassified site, morphology and/or behaviour codes. Ascertainment of cases by the Scottish Cancer Registration Scheme seems to be high for most sites. Pathology databases represent a useful additional source of cases but the fact that 71 apparently 'missed' cases were found to be ineligible for registration as independent primary malignant neoplasms suggests that unverified computerised pathology data should not be used uncritically nor independently for cancer registration purposes.