Genome size were estimated for three species of forensically relevant flesh flies (Diptera : Sarcophagidae) collected from three different regions in Egypt. Genome sizes of Wohlfahrtia magnifica ranged from 1040.56 in Edfo to 1229 Mbp in Aswan, the Sarcophaga argyrostoma genome was 863 Mbp in Benha to 1045.87 Mbp in Edfo and finally the genome size of Sarcophaga dux was 1552.17 Mbp as estimated for one individual. These estimates are useful not only as preliminary information for some molecular and genomic studies, but also for determination of the species through immatures. Genome size represents an additional tool for species identification in the immature stages, where they are morphologically difficult or impossible to identify. Sarcophagidae can be differentiated by using Cytochrome Oxidase I, but flow cytometry can be faster than sequencing. Genome sizes appear to vary in a discontinuous fashion. This is the first study to produce genome size estimates for Egyptian Sarcophagidae species. More work will need to be done to determine if there is sexual dimorphism, cryptic species, or polyploidy in Wohlfahrtia magnifica and Sarcophaga argyrostoma populations.