Measurements of CO2 concentrations in the atmosphere and in the surface waters of the South Pacific Ocean were made by NOAA scientists between 1984 and 1989. These basin-wide measurements were all taken during austral autumn and provide data for evaluation of the seasonal flux of CO2 from this region. The sensitivity of this flux to the uncertainty in the CO2 gas exchange coefficient was evaluated using four different wind data sets and two formulations for the wind dependence of gas transfer velocity. The integrated net flux of CO2 to the atmosphere during austral autumn (February to May) ranges from -0.03 (ocean influx) to +0.09 (ocean efflux) GT of carbon depending on the combination of wind field and wind-dependent exchange coefficient used. ¿ American Geophysical Union 1991