e20544 Background: Poor sleep is common, and is linked to impaired cognitive, psychological, and physical functioning and a lower quality of life. The purpose of this study is to measure quality of sleep in cancer patients and determine the relationship between quality of sleep and performance status. Methods: Patients with cancer (n=139) were recruited at the public hospital between November 2011 and January 2012 and asked to complete the Pittsburgh Sleep Quality Index (PSQI) and the Eastern Cooperative Oncology Group (ECOG) performance status (PS) questionnaires. Twenty patients repeated the questionnaires after 3 months. For the purpose of this study PSQI global score >5 was considered insomnia. PS score 0-1 was considered good, and PS 2-4 was considered poor. Results: The mean age of participants was 55±11 years, 56% were women, 78% were ethnic minority, 77% had advanced cancer, and 71% were undergoing cancer treatment. Among all patients, 73% reported good PS. Median PSQI score was 7 (IQR 4; 11) and 62% had insomnia. Sleep medication was used by 25%. Patients with poor PS had worse PSQI score (Mann-Whitney test, p< 0.0001), and 7.34 (95%CI 2.11-25.49) higher odds of insomnia (p=0.0002) compared to patients with good PS.(Table1) No significant correlation was found between insomnia and gender, ethnicity, primary tumor type, tumor stage, or treatment status. Conclusions: The incidence of insomnia among cancer patients is high. There is a higher incidence of sleep disturbance and worse sleep quality among patients with poorer performance status. [Table: see text]