Sex determination from a single or a part of bone is always difficult in absence of other bones of the same individual. The current study is an attempt to know the sex of an individual from the study of posterior ramus of mandible. The study was done from December, 2014 to August, 2015 in various Medical Colleges of the state of Odisha, India with the use of morbid anatomical specimen of mandibles and simple measuring instruments. The posterior ramus of adult mandibles were studied for presence or absence of any notching and if present its position in relation to occlusal plane. The study resulted, that there was a role of notch position in sex determination. The presence or absence of the notch though was not a consistent finding of all the mandibles. Males had frequent notching at the level of occlusal plane (P< 0.01) and females had frequent notching above the occlusal plane (P < 0.01). Notch present below the occlusal plane had no relation with sex. Accuracy of sexing mandible from the posterior ramus notch position was 61%, which was more for males (68.57%) as compared to females (43.33%). So the posterior ramus of mandible could be considered for determination of sex of mandible but this should not be the sole criteria and should be correlated with the other standard criteria.