Fifteen species and three subspecies of foraminifera and forty-four species of ostracods are described from subsurface borehole Horus Well- in the northwestern desert of Egypt. The stratigraphic significance of some benthonic foraminifera (Thomasi- nella, Nezzazata and Nezzazatinella) furnish new information on the age determination. Cenomanian-Santonian time is suggested for the studied interval (Bahariya and Abu Roash Formations). Among the identified ostracodes, three species of Bairdia are described for the first time: B. bassiounii, B. compressa, and B. elongata. Also, one new subspecies of Nezzazata, N. convexa conica, is discussed. The identified foraminiferal species belong to 12 families: Thomasinellidae, Mayncinidae, Nezzazatidae, Textulariidae, Hauerinidae, Vaginulinidae, Heterohelicidae, Hedbergellidae, Favusellidae, Discorbidae, Rosalinidae, and Cibicididae. The identified ostracodal species belong to 12 families: Cytherellidae, Bairdiidae, Bythocyprididae, Paracyprididae, Brachycytheridae, Bythocytheridae, Cyth- erideidae, Cytheruridae, Loxoconchidae, Progonocytheridae, Trachyleberididae, and Xestoleberididae