A systematic lithostratigraphical description is presented of those Jurassic rocks encountered in Egypt north of 290N9 at surface and in the subsurjace. Based upon the scheme first proposed by Al-Far (1966), five formations (Masajid, Khatatba. Bir Maghara, Shusha and Rajabiah) are shown to make up a continuous succession from late Pliensbachian probably up to early Tithonian: the Gebel el Maghara Group. The compositions of stratigraphically-useful and diverse biotas are outlined, and used to erect a chronostratigraphical framework. From this, reliable comparisons are made with the Jurassic sequences of Palestine and Saudi Arabia. Furthermore, this more refined means of correlation enables a fuller understanding of the distribution of potential Jurassic source and reservoir rocks in northern Egypt.