The effects of Coffea cruda 30 and 200c and caffeine on the sleep pattern of rats were investigated. Treatments were administered orally at the beginning of the sleeping period. EEG from the parietal region was recorded. Delta (0.5-2.5 Hz) and slow (< 1 Hz) waves are two of the major oscillation types that characterize neocortical electrical activity. The spectral power in these bands and the power ratio between 0.32-0.48 Hz and the delta band (slow/delta power ratio) for control and treatment groups were analyzed blind. Power in the delta band was significantly higher than baseline for Coffea 30c and caffeine (15.5mg/kg). An increase in the slow/delta power ratio between control and treatment was detected for Coffea cruda 30 and 200c. Coffea 30c and caffeine have similar effects on sleep pattern, enhancing delta power; Coffea cruda 200c appears to affect only the synchronization.