The history of bomb-produced radiocarbon in the surface waters of the Red Sea and the western Gulf of Aden was reconstructed from annual growth bands of corals. Gulf of Aden surface water entering the Red Sea and flowing to the north at the surface of the Red Sea becomes progressively enriched in bomb 14C by air-sea exchange of carbon dioxide. With physical oceanographic observations and analysis as the basis of a simple model, this progressive northward enrichment can be used to calculate a mean invasionn flux for CO2 across the Red Sea surface. The CO2 invasion flux so calculated is 8 mol/m2/yr with an uncertainty of approximately 2 mol/m2/yr. When combined with the extensive historical observations of wind speeds in the Red Sea, the calculated CO2 invasion flux supports the empirical relationship between CO2 invasion and wind speed proposed by other workers. Sea surface pCO2 was measured at seven stations along the length of the Red Sea in January 1985. These pCO2 data show that in midwinter the net flux of CO2 across the Red Sea surface (i.e. the difference between the invasion and evasion fluxes) is approximately zero for the Red Sea as a whole. ¿ American Geophysical Union 1989