The aim of this study was to investigate nursing staff induced repositionings and the patients' spontaneous movements during the day and night among older immobile patients in nursing care. Furthermore, the aim was to identify factors associated with the nursing staff induced repositionings and the patients' spontaneous movement frequency. An observational cross-sectional design was used. Spontaneous movements among patients (n = 52) were registered continuously using the MovinSense monitoring system. The nursing staff documented each time they repositioned the patient. Patients spontaneous movements were compared with nursing staff induced repositionings. There were large variations in the patients' spontaneous repositioning frequency during both days and nights, which shows that, although immobilised, some patients frequently reposition themselves. Analgesics were positively related to the movement frequency and psycholeptics were negatively related. The nursing staff more often repositioned the patients who were assessed as high risk than those assessed as low risk, but the patients' spontaneous movement frequency was not correlated to the risk score. This may be important when planning repositioning schedules. A monitoring system may be useful in decision making with regard to planning repositioning and positions used in the prevention of pressure ulcers among elderly immobile patients.