Sleep is a basic need, important to physical and psychological recovery. Insomnia implies sleep-related complaints, such as difficulty falling asleep, difficulty staying asleep, early awakening, or non-restorative sleep (NRS) in an individual who has adequate circumstances and opportunity to sleep.  Insomnia is also related to impairment of daytime functions. The prevalence of reported sleep disturbances varies between 15% and 60% in patients with coronary artery disease (CAD) up to five years after intervention. Disturbed sleep may have a negative impact on self-care capacity and behaviours. Little attention has been given to evaluation of sleep promotion through individualized non-pharmacological interventions among CAD patients. The overall aim of this thesis was to describe the impact of sleep quality and disrupted sleep on health-related quality of life (HRQoL) in patients with stable CAD, in comparison to a population-based group. The objective was also to evaluate an individualized non-pharmacological programme to promote self-care in sleep. Four studies were conducted during seven years, starting in 2001. Patients from six hospitals in the south of Sweden were invited to participate. In addition, an age and gender matched population-based group was randomly selected during the same period as the patients and was used for comparison with the CAD patients in two of the studies. Data was collected through interviews, self-reported questionnaires, a study specific sleep diary and actigraphy registrations. A pretest-posttest control design was used to evaluate whether an individualized non-pharmacological intervention programme could promote self-care in sleep-activity in CAD patients. The results showed a high prevalence of insomniac CAD patients out of whom a large proportion were non-rested insomniacs. This showed that NRS is one of the core symptoms of insomnia. On the other hand there were weak or non-significant gender differences with increasing insomnia severity. Severe insomniac CAD patients displayed a two or threefold higher presleep arousal or anxiety score and were more limited in taking physical exercise than the general population. Generally low sleep efficiency (SE%) was revealed in the studies, particularly among severe non-rested insomniac CAD patients. Among CAD patients, the individualized non-pharmacological programme to promote self-care in sleep-activity indicated improvements in sleep and HRQoL. This thesis elucidates the importance of focusing on the individual’s perception of their sleep-activity and health in their local context and supporting self-care management. Furthermore, it is of importance that nurses set individual goals together with the patient in order to increase self-efficacy to promote HRQoL.