The present study made a modest attempt to compare the income of the mango farmers from different sources and estimate the costs and returns of mango production in the study area. Data was collected from ninety mango growers from six villages of Bhagalpur district of Bihar following multi-stage sampling technique. The cost of cultivation of mango was estimated adopted the standard methodology as per CACP. Discounted cash flow, NPW, B-C ratio and IRR technique was employed to evaluate the investment analysis of mango. Majority of the sample farmers (56.67%) earned their livelihood from non-agricultural and agricultural activities as well, whereas rest of them entirely dependent on agricultural and allied activities. The sample farm household earned Rs. 4.37 lakh/ annum on an average in last year in which Rs. 2.55 lakh (58.35%) was earned from agricultural activities and Rs. 1.82 lakh (41.65%) from non agricultural activities. The mango farmers generated net returns of Rs. 72,620 per acre on an average. The cost of human labour, amortized cost of initial investment, cost of irrigation and cost of plant protection chemicals were the major cost items contributing 31.69, 21.58, 14.21 and 12.57 per cent, respectively. The B-C ratio of mango production was 2.60 with an internal rate of return 27.13 per cent.