This study is intended to attain preliminary estimates on the potential for carbon credits for Small hydropower (SHP) projects in the Brazilian overview, which was divided into two phases. In Phase I, a comparative analysis was conducted of accumulated CO2 emission values by the expansion of gross annual sources of coal and the accumulated CO2 emission values from the expansion of the gross annual installed capacity of SHP for two scenarios, Scenario 1 and Scenario 2. The results demonstrated the advantages of using SHP as an energy source, with regards to greenhouse gases (GHG) emissions, despite the uncertainty of the values of GHG emission factors. Phase II presents a case study based on data from a real time series for a station located in southern Minas Gerais State with an arbitrary value for the design head of the venture. The calculation of Permanency Power, Energy Curve, and values of Optimum Hydraulic Power Available (MW) and Optimum Flow Available (m(3)/s) was made possible by the Microsoft (R) Excel (R) spreadsheet from CERPCH [11]. The calculation of net income derived from carbon credit for SHP projects was done through the Microsoft (R) Excel (R) spreadsheet from Michellis junior [18], based on the CDM guidelines as recommended in the UN Convention on Climate Change, Ministry of Science and Technology. The results showed that the net revenues obtained for carbon credits in SHP projects located in the Isolated System were well above those obtained in the National Interconnected System. (C) 2012 Elsevier Ltd. All rights reserved.