An optoelectronic sensor and method for detecting an object in a three-dimensional monitored region uses a plurality of video sensors. Each sensor has a multiplicity of light-receiving elements that are configured to take a pixel picture of the monitored space, and a control unit identifies an object in the monitored space from video data of the pixel picture. Each video sensor has at least one pixel line that is formed by light-receiving elements. The video sensors are spaced from each other so that each sensor monitors an associated plane of the monitored space.