Background- Over the decades we are witnessing an increasing trends of substance abuse globally. Easy accessibility and work place stress adds on to the vulnerable medical students to indulge in various substance abuses. Here we aim to assess the pattern and prevalence of substance abuse among medical interns of a tertiary care hospital, Mangalore Karnataka. Methods- A cross sectional survey was conducted among consented 114 medical interns using a semi structured proforma in a tertiary care hospital, Mangalore Results- Prevalence of substance abuse were found to be 32% of which alcohol abuse was the highest followed by tobacco abuse and cannabis. Conclusion- Substance abuse was highly prevalent among medical students. Early intervention to curb the dependence pattern is very much essential as to maintain the integrity of medical fraternity.