Opisthorchis viverrini is an important trematode infection in the Northeastern Region of Thailand.Following a number of epidemiology studies and trial projects, the national liver fluke control program has been developed and operated under different National Public Health Development Plans. Presently, the program is being operated and focused on the northeastern provinces of Thailand. A survey in Non Sam Ran village, Borabue District, Mahasarakam Province where the high prevalence of opisthorchiasis was mentioned, was performed during October 1999. The setting was a village under the control program with annual praziquantel distribution. A brief survey of self-prevention behaviors towards intestinal parasite infection of the villagers was performed. Purposive sampling of 56 villagers from each available house in the village was performed. According to the questionnaires, all villagers admitted wearing shoes, avoiding eating raw food and using toilet. However, some (44.6 %) still disclosed using hand without washing before eating. In interest, most (89.3 %) replied self-prescribing antihelminthic drug to get rid of their own intestinal parasites. Furthermore, we also performed stool examination in all 56 sampled villagers (16.2 %). In interest, there was no case of opisthorchiasis. However, 7 cases (12.5 %) of Ascaris lumbricoides infection and 7 cases (12.5 %) of Entamoeba spp infection were detected. Comparing to other nearby setting without previous control program, low prevalence of trematode infection in our studied community is detected. However, the high prevalence of nematode and protozoa infections in this setting was still observed. Nevertheless, some poor hygienic practice such as using hands without washing before eating, due to the traditional belief are still detected.