The object of this study was to assess the relative risks of cancer for a particular branch of industry by using the newly created cancer environment registry. The registry was created by a record linkage of the 1960 census to the Swedish Cancer Registry 1961-73. A cohort study was undertaken of all subjects classified in the census as working in the electronics or electrical manufacturing industry. The risks were calculated in relation to the general working population. The results showed a slightly higher total incidence of cancer (all sites) in this branch of industry than in the general working population, for men as well as for women. This was especially so for tumour sites connected with the pharynx and the respiratory system. The study also indicates that the new registry has a potential as a screening instrument.