In light of low cancer rates by the Mormon Church, this study classifies female Mormon cancer patients in Utah according to measures of adherence to Church doctrines. The distribution by Church activity level is compared for each site to a group of other cancer sites felt to represent the overall activity level distribution of Utah Mormon women. Mormon women classified as having the strongest adherence to Church doctrines had lung cancer rates during 1966-1970 much lower than did women with the weakest adherence. The relationship was not as strong, however, as that seen in Mormon men when classified by lay priesthood office. Cancer of the uterine cervix also showed lower rates in the more active groups, but this finding was not statistically significant. Cancers of the breast and ovary did not show consistent associations with Church activity level, nor did most of the gastrointestinal cancers. These data suggest that some of the differences in cancer incidence between Mormons and non-Mormons may not be explained by adherence to specific Church doctrines.