No population-based cancer registry exists in Malaysia; thus our main sources of incidence data were biopsy series. We determined the frequency of cancers by body site, sex, and ethnic group from biopsy records of the Division of Pathology of the Institute for Medical Research in Kuala Lumpur for the years 1969-71. We then made comparisons of leading sites with data from the Singapore Cancer Registry. Relative risk values for 21 sites indicated significant differences among ethnic groups for cancers of the nasopharynx, larynx, lung, bone, skin, cervix, ovary, prostate, and penis and for lymphomas.