Abstract: The Jurassic–Lower Cretaceous petroleum system in the northern Rub’ Al-Khali Basin contains some of the largest oil and gas accumulations of the Middle East. Carbon isotopes and biomarkers indicate that the main source of hydrocarbons originated from the Jurassic-aged Tuwaiq Mountain and Hanifa basinal source rocks. Other source rocks, despite being less significant and being often overlooked, have also contributed in considerable amounts to the charge and include the Jurassic Jubaila and the Lower Cretaceous Habshan, Thamama and lower Bab intervals. All these source rocks are marine carbonates and the kerogen type is mainly, but not exclusively, represented by the oil-prone, low-activation energy and sulphur-rich type IIS. We are presently reviewing the stratigraphic setting of the source rocks to better map out their thickness distribution and initial source rock properties.