We have investigated the effect of nurse and patient education on oxygen mask placement after surgery. In 15 patients, each studied for 8 h, masks remained positioned correctly in two and were removed a total of 37 times in the others. Median total removal time per patient (4 min 3 s) was less than in previous studies and maximum total time of mask removal was 1 h 33 min 57 s. Masks were removed for longer than 10 min on four occasions in two patients. None of these removals was for nursing care. This is an improvement compared with previous studies.