Heat production measurements from the West-African shield have been compiled using various samples of crustal rocks. There is no clear indication for a systematic variation of heat production with age which could explain the regional heat flow density (HFD) variations by corresponding variations of the crustal component. HFD values are positively correlated with the P-wave travel time residuals deduced from teleseismic observations and negatively correlated with gravity isostatic anomalies. We propose that regional HFD variations are significative of change in the upper mantle structure. ¿ American Geophysical Union 1992