There is no doubt that REDD+ payments can do many activities that lead to deforestation and forest degradation less attractive. However, countries considering participating in REDD+ mechanism, need information on what it would cost them to reduce emissions from deforestation and forest degradation. This study was delimited to estimate transaction costs of REDD+ project with the Advancing REDD+ in Kolo Hill pilot project in Kondoa District as a case study. Socio-economic and biophysical data regarding routine, non-routine activities, their associated transaction costs and carbon stock were collected. The socio-economic data were collected through interviewing 40 households in Mnenia village while 39 sample plots were systematically established in the Mnenia forest. The qualitative data from structured questionnaires were analysed using the Statistical Package for Social Science (SPSS) while the quantitative data such as costs were analysed using Microsoft excel spreadsheet. The carbon stock were analysed using locally allometric equation that estimated the biomass and converted into carbon by multiplying biomass by 0.49. The routine and non- routine identifed were boundary making and attending the village meetings among others. The average total cost incurred in setting up and running by project stakeholders was US$76.06ha-1 while the average carbondioxide stored was 72.48tCO2eha-1. The average costs incurred by managing the forest in relation to a tCO2 stored was $1.0485tCO2e-1ha-1. Estimates suggest that abatement transaction cost in Non-Annex I countries ranges between 0 - 3.48 US$tCO2e-1ha-1 for projects. According to the available carbon stock and costs incurred, the project was found to be economically profitable at 5%, 10%, 15% and 25% discount rates with NPVs of about US$19021.92, US$9061.366, US$5426.22, US$3754.257 and US$2838.799 respectively. Although the estimates suggest that abatement costs observed was between the ranges on the estimates in Non-Annex I countries more investigation should be done to other forest ecosystems so as to establish abatement cost in Tanzania.Climate Change Initiative, Adaption and Mitigation (CCIAM)