Potassium-argon ages are presented for nine alkaline ring complexes in the Southeastern Desert of Egypt, with two or more dates for six of them. The ages range from Cambrian to Cretaceous. This contrasts with the previously held opinion that the ages of these complexes were Mesozoic-Cenozoic. A range in emplacement ages within any particular complex could not be discerned. This limits the time span of emplacement of any complex to less than a few million years. There is no obvious tectonic significance in the overall distribution of the ages. The intrusions happened periodically in time. Their ages are multiples of 52 m.y. plus 38 m.y.