to evaluate the characteristics of sleep and the factors associated with the quality of sleep in elderly patients receiving outpatient chemotherapy treatment. cross-sectional study with 140 elderly patients (51.2% female, average age 69.8 years) with stage III or stage IV cancer (67.9%), undertaken in a university hospital in the state of São Paulo in 2010. The following instruments were used: sociodemographic and clinical characterization questionnaire, validated by specialists; Pittsburgh Sleep Quality Index; Piper Fatigue Scale-reviewed; and a scale for the subjective measurement of pain. the majority of the elderly (62.9%) had a score compatible with poor sleep quality. On average, the duration of sleep was 388.0 minutes, latency was 44.6 minutes and efficiency of 83.8%. Through multiple logistic regression analysis, an increase of 21% in the probability of having poor sleep quality was observed for each single-point increase in the intensity of the pain. nursing interventions aiming to promote better sleep quality for elderly patients with cancer must include measures for pain control.201100-8