The present study was undertaken to investigate the influence of apneas on REM-elicited dream reports, and to examine the influence of clinically successful treatment of the apneas on dreaming. Thirty-three volunteers suffering from sleep apnea syndrome (SAS) slept during two nights in the sleep laboratory. Sixteen were treated with nasal continuous positive air pressure (CPAP) during the first night and 17 during the second. There was a total of 150 awakenings. 78 from REM sleep without apneas, and 72 from REM sleep with apneas. After apneas, dream recall tended to be higher (60% vs. 72%, p = 0.09) and dream reports were significantly longer (16 words vs. 24 words, p = 0.05), than after healthy sleep. No systematic incorporation of the apnea stimulus into the dream reports could be demonstrated. Dreams after apneas were found to be significantly more negative than dreams after healthy sleep (p < 0.01). This suggests that REM-elicited dreams are basically resistant to powerful internal stimulation. The stress caused by the apneas exerted only a very global emotional influence on manifest dreaming.