This study describes the health-related quality of life (HRQoL) of day-surgery patients and aims to identify factors associated with HRQoL. The cross-sectional questionnaire survey data were collected from day-surgery patients being discharged from hospitals in one Finnish hospital district in 2001 using the Nottingham Health Profile (NHP). The analysis was based on statistical methods. Day-case surgical patients had the best HRQoL in the social dimension and mobility. The NHP scores showed moderate distress in sleep and energy, and demonstrated pain. Older age and vocational education were associated with higher scores as measured with the NHP, indicating more problems in the measured variables. The patients who have been operated as day cases recovered satisfactorily and the operation did not weaken their perceived HRQoL. More emphasis should be put on evaluating day-case surgery patients' pain. Patient's age should be taken into account in planning type of surgery. The NHP is also a useful tool for the purposes of studying the HRQoL of day-case surgery patients.