This research studys main objectives were to investigate the demographic, social, economic and illness characteristics of persons who use traditional and herbal medicines, and to examine the correlation between these characteristics and patterns of medicinal use Study data were drawn from the Survey of Health Welfare and Traditional Medicine Use in Thailand 1986 as well as the Labour Force Survey conducted by the National Statistical Office from May 16 -June 15, 1986. The sample consisted of 16,658 users of traditional and herbal medicines. Results indicate a statistically significant correlation (at .05) between traditional and herbal medicine use and the studys independent variables which included region, age, sex, occupation and symptom manifestation. However, no statistically significant correlation (at .05) existed with regard to such medicinal use and factors associated with area of residence educational level, disease severity and illness duration. Regarding traditional medicine, persons living in Thailands Central region most frequently used this type of medicine, however no statistically significant difference existed between persons residing in rural versus urban areas. The findings also showed that children aged 0-5 and 6-12 years used traditional medicines to the same extent but much more so than any other age groups. Women also used traditional medicines more than men. Persons with high and low levels of education used traditional medicines to the same extent as herbal ones, though students used traditional medicines more than persons in other occupational groups. Concerning type of disease, patients with chronic diseases used traditional medicine to the same extent as patients suffering from acute diseases. For duration of illness, no differences were noted concerning traditional medicine use However, this type of medicine was used most frequently for disorders of the digestive system. Concerning herbal medicine, this study revealed that persons residing in the Northeast region used this type of medicine to a greater proportion than people living in other regions. Once again, no difference existed between rural and urban areas with regard to herbal medicine use. People aged 46-59 years used herbal medicine most frequently compared to other age groups, though the amount used was approximately the same as that used by persons over age 60. Regarding sex differences, men used herbal medicines more than women. People with low levels of education also exhibited higher usage rates than those with a high education. Considering occupation, professionals and businessmen used herbal medicines more than other occupations. No difference existed, however, between duration and type of illness (chronic or acute), though herbal medicines were used most frequently for circulatory system disorders, It was shown that most results supported the postulated hypothesis except with regard to such variables as area of residence. education. severity of disease and duration of illness. The factors influencing patterns of traditional and herbal medicine use were analyzed using Analysis of Variance (ANOVA) and Multiple Classification Analysis (MCA). When each factor related to traditional medicine use was treated separately, it was discovered that illness factors could explain the variation independent variables most strongly, followed by demographic and socio-economic factors respectively. However, . when three groups of these factors were examined simultaneously using, these same analytical methods, results showed that they could explain traditional medicine use to the same extent as each single factor. This study indicated that region, occupation, sex, educational level, age and disease symptoms were associated with traditional medicine use at a .05 statistical level of significance. Of all of these factors, disease symptoms was the most highly associated with traditional medicine use and could explain the variation in it more than other variables.