Abstract. Health effects of exposure to fine particulate matter (PM2.5) in India were estimated in this study based on a source-oriented version of the Community Multi-scale Air Quality(CMAQ) model. Contributions of different sources to premature mortality and years of life lost(YLL) were quantified in 2015. Premature mortality due to cerebrovascular disease(CEVD) was the highest in India (0.44million), followed by ischaemic heart disease(IHD, 0.40million), chronic obstructive pulmonary disease (COPD, 0.18million), and lung cancer (LC, 0.01million), with a total of 1.04million deaths. The states with highest premature mortality were Uttar Pradesh (0.23million), Bihar (0.12million), and West Bengal (0.10million). The highest total YLL was 2years in Delhi, and the Indo-Gangetic plains and eastern India had higher YLL (1years) than other regions. The residential sector was the largest contributor to PM2.5 concentrations (40gm3), total premature mortality (0.58 million), and YLL (0.2 years). Other important sources included industry (20gm3), agriculture (10gm3), and energy (5gm3) with their national averaged contributions of 0.21, 0.12, and 0.07 million to premature mortality, and 0.12, 0.1, and 0.05 years to YLL. Reducing PM2.5 concentrations would lead to a significant reduction of premature mortality and YLL. For example, premature mortality in Uttar Pradesh (including Delhi) due to PM2.5 exposures would be reduced by 79% and YLL would be reduced by 83% when reducing PM2.5 concentrations to 10gm3.