The average contents of Zn, Cd, Cu, Co, Fe, Mn and Ni were measured seasonally in the ashes of Caulerpa racemosa, Cystoseira myrica, Digenea simplex, Hormophysa cuneiformis, Padina pavonica and Sargassum cinereum using Flame Atomic Absorption Spectrometry (AAS). The studied species were collected from three different sites along the northern part of the Red Sea coast during 2017. Cystoseira myrica recorded the highest Fe average (575.88 µg/g dry wt.) and Mn (164.12 µg/g dry wt.) in summer at Site II, Caulerpa racemosa recorded the highest Cu average (91.10µg/g dry wt.) at Site I in autumn, meanwhile Sargassum cinereum showed the highest averages of Zn and Co (33.88 and 16.56 µg/g dry wt.) in spring at sites II and III respectively. The highest averages Ni and Cd (10.46, 2.05 µg/g dry wt.) were observed in Padina pavonica at Site III in summer and spring seasons respectively. The obtained data indicated that the studied macroalgae have significant differential abilities to accumulate a certain heavy metals under the local conditions and it can be used as a good target for monitoring metals pollution in marine waters.