Background Sleep is essential for full mental and physical renewal. Cardiac surgery improves the life expectancy and quality. But unfortunately, some patients lacked that merit as they suffered sleep disturbance. We used validated questionnaire applied to 153 cardiac surgery patients to assess the sleep disturbances after surgery. Results About 70 (45.8%) had valve procedure, 55 (36%) had revascularization, 19 (12.4%) had both procedures and 9 (5.8%) had other procedures. The majority had no post-operative bleeding nor infection. About 78% had sleeping difficulty for one month. About 50% used different medications to fall asleep, mostly analgesics. About 76% slept after 2–6 h irrespective of sleep quality. Some patients had poor sleep quality in the form of nightmares and night terrors. Conclusion Sleep quality was disturbed immediately following cardiac surgery. There was a reduction of night sleep compensated by increased daytime sleepiness. These changes almost reverted one month after surge