Sport tourism is very popular with new generation tourists because they can enjoy recreation activity while improving their health and awareness towards environmental sustainability. The indirect benefit is reduction of air pollution and greenhouse gas (GHG) emissions from burning fossil fuel. The aims of this study were to estimate amount of carbon balance from energy consumption and reduction of sport tourism based on the case study from Benja Burapha Cycling Rally, Sa Kaeo province, Thailand. CO2 emission from fuel consumption of tourist transportation and CO2 reduction by cycling rally and tree plantation were calculated according to the 2006 Intergovernmental Panel on Climate Change (IPCC) guidelines. 108 questionnaires were distributed to the tourists. The results found that the ratios of male and female were 68 % and 32 %. The average distance between home and start destination at Pang Sida National Park, Sa Kaeo province, was313.79 ± 204.60 km. Total gasoline and diesel consumption for transportation was 1,127 and 1,409 L. Total GHG emission for fuel consumption was 6,333 kg CO2-eq. The average GHG emission per person of transportation was 27.43 kg CO2-eq. The GHG reductions from the bike cycling and tree plantation were 1,448 kg CO2-eq and 1,786 kg CO2-eq y-1. The total CO2 emission and reduction of the sport tourism were27.43 and 36.37 kg CO2-eq person-1. The net CO2 balance of the sport tourism was -8.94 kg CO2-eq person-1 y-1.