The present invention refers to an automatic animal posture conditioning system, comprising at least one mobile device (1) (2) fixed to the body of an animal by a suitable mechanical means and, depending on the embodiment, by one or more external devices (3). The mobile device (1) and the auxiliary mobile device (2) comprise a collection of means for collecting data which enable to identify the relative angular position between the various parts of the animal body, animal body oscillatory movements and animal body static accelerations. In addition, the mobile device (1) comprises a set of means for applying sensory stimuli to the animal, whenever the latter adopts an unwanted posture. In addition, the mobile device (1) includes a central data processing unit, which processes the data that it receives from the various components, which verifies whether there is an infraction or not, and if any, that defines what stimulus to be applied to the animal.