Objectives: 1.To determine misconceptions associated with AIDS, Leprosy and Cancer. 2. To see the association of literacy with misconceptions. Materials and methods: A community based cross sectional study was conducted to determine the misconceptions about AIDS, Cancer and Leprosy in the Rural Pondicherry. A pre-tested semi-structured questionnaire was used. One village was selected randomly for the study, under the field practice area of Rural Health Centre. Besides socio-demographic information, questionnaire included sections on misconceptions related with diseases. Data were analyzed using SPSS software. Simple proportions and Chi square test were used wherever required. Results: Total 339 subjects were interviewed. Commonest misconception about AIDS was ?HIV Infected pregnant mother will surely transmit infection to child? (55.6%). Regarding misconceptions about Leprosy commonest (21.5%) was ?leprosy can__ampersandsignlsquo;t be cured completely? and for Cancer commonest misconception was ?Cancer can__ampersandsignlsquo;t be prevented? (31.9%).There were no significant differences about leprosy and Cancer misconceptions between illiterates and literates. Conclusion: In our study we found that misconceptions about diseases are deep rooted and there are insignificant differences between literates and illiterates.