The Euphrates River is one of the longest rivers in Iraq with five main tributaries along its course. But without any tributary inside Iraq. The river flows from eastern highlands of Turkey then through Syria and enters into the Iraqi territory from central western part and runs westwards to the central part of Iraq and then meets with the Tigris River in the southern part. The geology of the Euphrates River’s basin is presented with emphasize on the Iraqi part. Besides, the stratigraphy of the basin, the tectonic style, main geomorphological features and minerals’ resources are presented within the basin too. Wide range of rocks; age wise are exposed in the basin, with different economic potentials at different parts of the basin. This study is a unique one, which deals with the geology of the Euphrates River’s basin. It is conducted using the most relevant updated geological data.