Background: Sleep disturbance, including insomnia disorder, is common among patients with chronic health conditions, and is associated with psychological difficulties and impaired health-related quality of life (HRQoL). Less is known about whether a similar relationship exists in individuals with chronic health conditions who do not have a clinical diagnosis of sleep disturbance (NCSD). Recent evidence suggests that Cognitive Behavioural Therapy (CBT) in the form of self-help (SH) is an effective treatment for individuals with chronic health conditions and has the advantage of low cost and ease of access. Any form of sleep disturbance may be perceived as problematic for individuals with chronic health conditions. This study aims to: a) examine whether the NCSD population with chronic health conditions at baseline have poor sleep quality, insomnia symptoms, high levels of psychological distress (anxiety, depression and stress), sleep-related dysfunctional beliefs and impaired HRQoL, and b) assess the effectiveness of the CBT-SH booklet. Method: Participants were recruited from outpatient clinics and received a 6-week CBT-SH booklet for sleep-related problems. Outcome measures included evaluations of subjective sleep quality and the severity of insomnia symptoms, psychological distress (anxiety, depression and stress) sleep-related dysfunctional beliefs and HRQoL. Measures were completed before and after the intervention. Results: Forty-nine participants (44 females) completed the study. Prior to the intervention, 46 participants reported poor sleep quality and 47 participants reported clinical or subthreshold insomnia. Mean scores for the measures of psychological distress indicated moderate levels of anxiety, depression and stress and sleep-related dysfunctional beliefs respectively. HRQoL was also impaired. Following the CBT intervention, participants showed significant improvements in sleep outcomes, sleeprelated dysfunctional and stress levels. No significant differences were found in HRQoL depression and anxiety outcomes. Conclusion: A brief CBT-SH booklet for sleep-related problems is effective for patients with chronic health conditions and NCSD in clinical settings.