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Fore-arc basins of Western Indonesia are considered to have low hydrocarbon prospectivy because of several dry holes in the past. However, based on present interpretation using newly acquired 2D seismic data supported by postmortem well evaluation indicates interesting geologic evidence toward better understanding of fore-arc basins geology and tectonic evolution. As a result, new hydrocarbon exploration opportunity in frontier basins in Indonesia should not exclude the fore-arc area, which is mostly still underexplored. This paper will discuss results of fore-arc basins geological evaluation in western Indonesia particularly Bengkulu sub-basin as well as their hydrocarbon potential based on integrated surface geology and newly acquired 2D seismic data, supported by the current knowledge of regional tectonics. The fore-arc region of western Indonesia is distributed for more than 2000 km. The sediments within the fore-arc basin are mostly very thick consisting of shale, sandstone and limestone deposited in various depositional setting including deltas, shallow marine, slope and deep marine turbidities. It was very clear evidence from wells and seismic data that this region developed as a fore-arc basin since Early Miocene. However, numerous examples of pre-Miocene graben fill were seen in the new 2D seismic data interpretation. Therefore, this evidence suggests possibilities that older rift basins consisting of lacustrine deposit underlie fore-arc basins. Basement composition is considered as an important parameter in determining the hydrocarbon prospectivity of the region. Most of the areas are interpreted to be underlain by transitional crust consisting of previous subduction mélanges and older fore-arc sediments except for North Sumatra and South East Java, which are show evidence of continental crust. Deformation in the fore-arc region is relatively low except some shows evidence of series complex faults system. Our study indicates moderate hydrocarbon potential with evidence of hydrocarbon shows in some wells indicating thermogenic petroleum system occurrences.