A research study examined the relationship between illiteracy and health. The study used the following methods for gathering information: review of health status data from major Canadian health status surveys; multidisciplinary literature review across areas including medicine, health education, development, literacy, education, poverty, and socioeconomic status; questionnaire sent to health and literacy organizations across Ontario; three case studies at different sites in Ontario; and key informant interviews. The major finding was that illiteracy had a major, negative impact on health. This finding was consistent across a wide variety of measures of health status, including overall levels of mortality and morbidity, self-rated health, activity limitation, infant development, accidents, and a wide range of diseases. Evidence suggested that illiteracy leads to poorer health through a combination of both direct and indirect intervening variables. Potential solutions are grouped under the headings of social policy action, heightened awareness within the health community, working together with the community, provision of health information in nonwritten forms, and simplification of written information about health. (Appendixes include 93 references and observations of community organizations about health and literacy problems.) (YLB)