Quality of drinking water always remains a sensitive issue since contaminants like Arsenic, Fluoride in excess amount cause serious health hazards. Arsenic in drinking water causes harm to physical and mental health of a person and this may even cause cancer and damage to blood vessels and heart. This may also cause reproductive problems and birth defects.Several states of India are known to be effected arsenic contaminated water which leads to serious illness. Uttar Pradesh, Bihar, Jharkhnad, West Bengal, Assam, etc. are examples of such states. Arsenic related illness has also been reported in Manipur. Similarly presence of excess fluoride in drinking water causes mild dental fluorisis to skeletal fluorisis. It is also equally important to maintain prescribed standard of the other drinking water ingredients. Quality assessment of drinking water from Dimapur district of Nagaland and Karbi Anglong district of Assam has been presented in this paper. Quality assessment has been accomplished by measuring various quality parameters in drinking water collected from different random locations of the two districts. Quality parameters like ‘Alkalinity’, ‘Hardness’, ‘pH’, ‘Arsenic’ and ‘Fluoride’ concentration etc. are determined during the course of the study. Based on the values of the quality parameters, a rational analysis has been made about the quality of drinking water.