A method for calibrating the orientation of a video camera onboard a moving vehicle, said vehicle being aligned along an axis, known as the axis of the vehicle, the orientation of the camera being fixed with respect to the vehicle during an observation period and said vehicle keeping a constant course during said period with reference to a local land reference frame (OX t, OY t, OZ t), the camera taking at least two images of the vehicle environment in two distinct instants of said period, the camera being fitted with three accelerometers disposed along three orthogonal axes, two of which being located in the image plane of the camera, the method comprising the following steps: - matching a plurality of points respectively belonging to these two images, a pair of matched points being likely to have a same physical point of said environment; - determining (330, 340), from the respective coordinates of the matched points within both successive images, the components of a vector giving the moving direction of the camera between these two images, expressed in a reference frame related to the camera, said vector being determined as the translation vector of the camera between these two images and the components of this vector in the reference frame related to the camera being obtained from a decomposition of the essential matrix or the fundamental matrix associated with these two images; - measuring the rolling and pitching angles of the camera using said accelerometers and calculating the projection in the horizontal plane (OX t, OY t) of the local land reference frame (OX t, OY t, OZ t) of said vector thus obtained by means of the rolling and pitching angles thus measured and deducing from the components of the vector thus projected ( U T), an estimation of the angle between the optical axis of the camera and the vehicle axis, as seen in the horizontal plane (OX t, OY t) of the local land reference frame (OX t, OY t, OZ t). - matching a plurality of points respectively belonging to these two images, a pair of matched points being likely to have a same physical point of said environment; - determining (330, 340), from the respective coordinates of the matched points within both successive images, the components of a vector giving the moving direction of the camera between these two images, expressed in a reference frame related to the camera, said vector being determined as the translation vector of the camera between these two images and the components of this vector in the reference frame related to the camera being obtained from a decomposition of the essential matrix or the fundamental matrix associated with these two images; - measuring the rolling and pitching angles of the camera using said accelerometers and calculating the projection in the horizontal plane (OX t, OY t) of the local land reference frame (OX t, OY t, OZ t) of said vector thus obtained by means of the rolling and pitching angles thus measured and deducing from the components of the vector thus projected ( U T), an estimation of the angle between the optical axis of the camera and the vehicle axis, as seen in the horizontal plane (OX t, OY t) of the local land reference frame (OX t, OY t, OZ t).