Pose estimation is typically performed through 3D images. In contrast, estimating the pose from a single RGB image is still a difficult task. RGB images do not only represent objects’ shape, but also represent the intensity that is relative to the viewpoint, texture, and lighting condition. While the 3D pose estimation from depth images is considered a promising approach since the depth image only represents objects’ shape. Thus, it is necessary to know what is the appropriate method that can be used for predicting the depth image from a 2D RGB image and then to use for getting the 3D pose estimation. In this paper, we propose a promising approach based on a deep learning model for depth estimation in order to improve the 3D pose estimation. The proposed model consists of two successive networks. The first network is an autoencoder network that maps from the RGB domain to the depth domain. The second network is a discriminator network that compares a real depth image to a generated depth image to support the first network to generate an accurate depth image. In this work, we do not use real depth images corresponding to the input color images. Our contribution is to use 3D CAD models corresponding to objects appearing in color images to render depth images from different viewpoints. These rendered images are then used as ground truth and to guide the autoencoder network to learn the mapping from the image domain to the depth domain. The proposed model outperforms state-of-the-art models on the publicly PASCAL 3D+ dataset.