The topographical distribution of alpha activity (8.125-11.125 Hz) in the REM sleep EEG, its time course within and across REM sleep episodes, and the effects of selective REM sleep deprivation were investigated in 8 young males. Power spectra of bipolar derivations along the antero-posterior axis in the left (F3C3, C3P3, P301) and right (F4C4, C4P4, P402) hemisphere were calculated. Alpha activity increased along the antero-posterior axis in both hemispheres, and was dominant in the right hemisphere. It decreased within and across REM sleep episodes. Selective REM sleep deprivation resulted in a reduction of alpha activity in the REM sleep EEG. However, the topographical distribution and the time course were not affected. It is suggested that alpha activity in the REM sleep EEG is a marker of REM sleep homeostasis.