Abstract: The solubility of Pr in barium titanate was studied within the framework of a final undergraduate project. Two series of samples were investigated. The first one was a Ba-rich series. In this series it was found that the solubility limit is between 4-mol% and 10-mol% Pr, and the second phase that was found above the solubility limit was (Pr doped) Ba2TiO4. The second one had Ba/Ti ratio equals 1. In this series the solubility limit was between 15-mol% and 20-mol% Pr. DSC test on a sample with 10-mol% Pr and Ba/Ti=1 shows a very broad peak in the temperature range –50?C to 50?C. This can be a result of either valence change of the Pr ions on the Ti sites within that temperature range, in accord with earlier results, or a broaden rhombohedral-tetragonal phase transition of the barium titanate.