Abstract: A device for detecting and synchronising a position of at least one first wheel of a timepiece mechanism for an electronic analogue wristwatch, includes this first wheel extending in a plane. The detection and synchronisation device includes at least one light source emitting a light beam and at least one light detection system. A first light-reflecting element projects from one of an upper or lower surfaces of the first wheel of the timepiece mechanism. The light source and the light detection system are arranged so that in a determined position of the first wheel of the timepiece mechanism, the light beam emitted by the light source is reflected by the first light-reflecting element in the direction of the light detection system. The detection and synchronisation device is housed within a case of the wristwatch.