Indonesia is a country that is developing in various industrial fields, including the energy sector, namely geothermal power plants. In developing a geothermal project there are several factors, including cost overruns during the construction process. Therefore, the aim of this research was to develop an analytical framework for cost risks in developing geothermal projects in Indonesia, which is one solution to minimize cost overruns in the power generation sector. The cost-related risk components identified in this study are based on comprehensive literature. All cost risk components were grouped through a factor matrix and then involved 7 experts for their opinions. Data analysis uses reliability and validity tests. The results of this research found 10 causes including contractor planning, resource availability, site investigations and other reasons. The results of this research can be a guide for geothermal project stakeholders in Indonesia in reducing cost overruns.