Synoptic-scale easterly waves at 700 hPa have been studied over West Africa and the tropical Atlantic for the summers of 1979--1995. Spectral analyses (Fast Fourier and Wavelet Transforms) of 700 hPa meridional wind component along 17.5 ¿N enable to point out two band-periods, between 3 and 5 days and between 6 and 9 days. An example of each wave is shown. Composite analysis confirms the evidence of two such regimes of easterly waves during summer over West Africa and the tropical Atlantic. The 6--9-day wave regime differ from the 3--5-day wave regime by larger anticyclonic cells originated from the Libyan and the Azores areas, and by more northern tracks. ¿ 1998 American Geophysical Union