We propose joint geodesic depth propagation (JGDP) for two-dimensional-to-three-dimensional video conversion. To save substantial human effort and produce high-quality depth maps, we adopt a key-frame depth propagation strategy based on a geodesic distance. First, we perform block matching between current and reference frames to estimate motion vectors (MVs). Second, we conduct depth compensation from the reference depth map for obtaining the current depth map based on MVs. Finally, we refine the depth map using joint geodesic filtering. Experimental results demonstrate that JGDP achieves an average 2.4-dB gain in peak-signal-to-noise ratio and 0.019 gain in structure similarity over state-of-the-art depth propagation methods.