To assess the environmental quality of Sharm Al-Kharrar lagoon, Red Sea coast, Saudi Arabia, forty-five water samples were collected for nickel (Ni), zinc (Zn), arsenic (As), copper (Cu), lead (Pb), cobalt (Co), chromium (Cr), and cadmium (Cd) analysis using an inductively coupled plasma-mass spectrometer. Ni was the most abundant heavy metal (5.76 μg/L), followed by Zn (4.19 μg/L), As (2.07 μg/L), Cu (1.24 μg/L), Pb (0.28 μg/L), Co (0.26 μg/L), Cr (0.26 μg/L), and Cd (0.06 μg/L). Seawater analysis indicated higher average values of the heavy metals Pb, Zn, Ni, Cu, and As in comparison with the average oceanic concentration and those values recorded from Arabian Gulf, Gulf of Aqaba, Red Sea, and Mediterranean Sea. The higher average values of metals in seawater may be attributed to atmospheric input or anthropogenic sources, like electric power and water supply plants, Aramco company refinery, and Aramco residential area, which distributed along the lagoon.