PURPOSE: The goal of this study was to compare the standing posture of stroke patients with standing posture of healthy subjects. We have used an analysis of the centres of pressure sways. MATERIAL AND METHOD: The centres of pressure sways of the subjects were recorded on a force platform. Each subject have carried out 5 trials of 60 s while maintaining a static standing posture, with eyes opened and then closed. These sways were broken down into two spectral frequencies. The first ones being the sways of the vertical projection of the centre of gravity and the second ones being the difference between the centre of pressure and the centre of gravity, expressing the neuromuscular stiffness. RESULTS: The 6 hemiplegic patients were 53.3 +/- 5.3 years old. The time since the stroke is 35.1 +/- 29.9 months. The 5 healthy subjects were 47.2 +/- 6.6 years old. The results showed that the root mean square of the neuromuscular stiffness spectral frequencies for the hemiplegic group was higher than the one of the healthy group. CONCLUSION: The hypothesis could be in static standing posture, the stiffness of the hips adductors and abductors muscles and the ankles flexors and extensors muscles is higher for the hemiplegic group than the healthy group. This increase of the stiffness could be explained by a disturbance of the muscle tone or/and the muscle coordination found amongst the hemiplegic patients. This first study encourages us to use this methodology to assess the evolution of the standing posture for hemiplegic patients during the rehabilitation period.