The paper analyses the economic growth effects of the external debt a pooled data set of fourteen (14) West African countries over 1990-2002. The results show that external debt to GDP ratio and external debt to exports ratio have a significantly negative effect on economic growth-thus accepting the debt overhang hypothesis. The crowding out effect through debt service to exports ratio is rejected. External debt to GDP ratio appears to have a non-linear effect on economic growth. Thus, doubling external debt-GDP ratio from any initial level will reduce real GDP growth in West Africa by 2.06 percentage points (with investment) and by 2.46 percentage point (without investment). These results imply that the substantial reduction in external debt projected for the HIPCs (especially through the recently approved G8 debt relief proposals) by the time all of them reach their completion points would, ceteris paribus, directly add between 2.06 and 2.46 percentage points to their real GDP growth rates. However, the Laffer curve proposition does not apply to the effect of external debt to exports on growth since its coefficient remains consistency negative and significant but the squared coefficient was positive though only significant in the regression without domestic investment, adding only a meagre 0.002 percentage point to growth when external debt is doubled. Our results also show that current domestic debt reduces economic growth mainly by lowering the efficiency of investment rather than its volume. The paper concludes with some policy implications.