The principle objective of this study is to analyse the socio-cultural aspects of herbal drugs utilization in self-care and in traditional healer treatments. A village in Yasothorn province was selected for a case study. The data collection methods employed were participant observation, depth interview, and illness episode self recorded method. The results of the study show that the use of herbal drugs is one choice among alternative treatments in the local pluralistic medical system. Out of the total number of self care patients, 30.2 percent used herbs in the first step of illness treatment, 41.4 percent of the total illness episodes were treated with medicinal herbs in any steps. This shows that medicinal herbs are chiefly used by self-care treatments rather than prescribed by traditional healers. Regarding the factors which influence the use of herbs, there was significante difference in the use of herbal and modern drugs in moderate to servere illnesses and "folk-defined illnesses" The results showed that self-care patients generally used herbal drugs which were widely available. Single fresh herbs were used for minor illnesses. Moreover herbal drugs were used in combination with many other types of treatments. Traditional healers prescribed herbal drugs as the main treatment. Medicinal herbs prescribed by traditional healer were mostly in formula form, an combination with other rituals. Owing to the rapid social and economic changes, there is a trend of decreasing use of medicinal herbs for minor illnesses and "folk-defined illnesses", especially in the first step of treatment. This is mainly due to availability, and self- perceived efficacy of modern medicine. It is not solely the pharmacological effects of medicinal herbs which make them popular among self care patients. Socio-cultural factors, myths and placebo effects has important therapeutic effects. Any policy to promote herbal medicine should consider not only the scientific but also the socio-cultural aspects of herbal drugs utilization as well.