The present invention relates to a method for detecting a person's fall by analyzing a stream of video images coming from an image taking device, comprising: .cndot. Acquisition (21) of successive images of a determined scene； .cndot. selecting (23, 25, 27) at least one point of the scene in said images； .cndot. determining the movement (29) of each selected point by analyzing the displacement of said point in the successive images in the form of a temporal succession of oriented vectors proportional to the instantaneous speed of movement of said point； .cndot. calculating (31) the instantaneous acceleration of each point associated with each vector representing the instantaneous speed； .cndot. detecting a fall (33) when the determined instantaneous speed is greater than a predefined threshold speed and the instantaneous acceleration is greater than a predefined threshold acceleration. 13 11. System for detecting a person's fall by analyzing a stream of video images, comprising: .cndot. a device (3) for acquiring successive images of a determined scene； .cndot. means for selecting at least one point of the scene in said images； .cndot. a calculator of the movement of each point selected by analysis of the displacement of said point in the successive images in the form of a temporal succession of oriented vectors proportional to the instantaneous speed of movement of said point； .cndot. a calculator of the instantaneous acceleration of each point associated with each vector representing the instantaneous speed； .cndot. means for detecting a fall when the determined instantaneous speed is greater than a predefined threshold speed and the instantaneous acceleration is greater than a predefined threshold accelerationLa présente invention se rapporte à un procédé de détection dechute d'une personne par analyse d'un flux d'images vidéo provenant d'undispositif de prise d'images, comprenant :.cndot. Acquisition (21) d'images successives d'une scène déterminée
