Mucositis, a serious complication in head and neck cancer patients could be the cause for, or consequence of decreased activity of granulocytes in oral mucosal secretions. This in turn may be attributed to poor body immunity in such patients. In the present study, the phagocytic activity of peripheral blood granulocytes was evaluated to understand its role in mucositis,and concurrent immunosuppression. Granulocytes from 15 oral cancer patients were collected and tested for phagocytic activity, by assessing the percent phagocytosis and phagocytic index of the granulocytes towards candida albicans before and after radiotherapy. The results were compared with normal healthy subjects(n=15).Percent phagocytosis decreased significantly (p<0.001) in baseline samples compared to controls as well as in post treated samples when compared to baseline samples(p<0.05). Phagocytic index decreased significantly in the post treated samples as against the baseline samples (p<0.05) although the changes were non significant between controls and patients. This decrease in phagocytic activity was coupled with progressive mucositis , which suggests that the decreased functional activity of the peripheral granulocytes could be the underlying cause for the altered immune response in cancer patients subjected to radiation.