Purpose. To investigate sleep quality of hospital staff nurses, both by subjective questionnaire and objective measures. Methods. Female staff nurses at a regional teaching hospital in Northern Taiwan were recruited. The Chinese version of the pittsburgh sleep quality index (C-PSQI) was used to assess subjective sleep quality, and an electrocardiogram-based cardiopulmonary coupling (CPC) technique was used to analyze objective sleep stability. Work stress was assessed using questionnaire on medical worker's stress. Results. A total of 156 staff nurses completed the study. Among the staff nurses, 75.8% (117) had a PSQI score of ≥5 and 39.8% had an inadequate stable sleep ratio on subjective measures. Nurses with a high school or lower educational degree had a much higher risk of sleep disturbance when compared to nurses with a college or higher level degree. Conclusions. Both subjective and objective measures demonstrated that poor sleep quality is a common health problem among hospital staff nurses. More studies are warranted on this important issue to discover possible factors and therefore to develop a systemic strategy to cope with the problem.