The genetic relationships between four species of groupers: Cephalopholis oligosticta, C. sexmaculata, C. hemistiktos and C. argus, common coral reef fish in the Red Sea of family Serranidae were studied by using Random Amplified
Polymorphic DNA (RAPD) technique. Twenty random primers were used. Each primer was individually tested with the four fish species. Amplification products were resolved on agarose gel electrophoresis and visualized under UV light, then
photographed. The number and size of amplified DNA fragments showed a wide range of variation. Tabulation and analysis of the data using the genetic similarity coefficient were carried out. The highest genetic similarity observed was between C. hemistiktos and C argus and the lowest was between C. oligosticta and C.sexmaculata. Dendrogram analysis revealed three clusters: first, comprises C.hemistiktos and C. argus; second, contains C. oligosticta and (C. hemistiktos and C.argus); the third incompasses C. sexmaculata and (C. oligosticta, C. hemistiktos and
C. argus).