Sleep is an active nervous process, which is structured in phases characterized by subsequent cycles of various psycho-physiological phenomena. It performs vital, yet mysterious functions and is in all likelihood involved in many processes, including cognitive processes. In old age the internal structure of sleep changes, but these physiological variations allow, in healthy subjects, a satisfactory quantity and quality of sleep. Until now there have been no literature reports of studies regarding sleep quality in extreme old age. Our work describes the investigation of the quality of sleep in a sample of 180 centenarians selected from the registered residents of Rome. We have studied sleep disorders, related pathologies and pharmacological treatments. The results of the study show good sleep quality for 57.4% of the sample group; 35.2% complain of medium intensity problems, significantly related to angina pectoris and to chronic obstructive bronchopneumopathy. Only 7.4% of the subjects showed severe problems, significantly related with cognitive deficiency and lower survival rate. The results of our study confirm, in centenarians as in the elderly, the existence of a positive correlation between sleep quality, survival and successful aging.