It could be shown that the hydrogen (H-2) treatment of lead iodide (PbI2) is capable to effectively reduce oxidic impurities contained in the source material used for single crystal growth. Comparative experiments of melting PbI2 in H-2 and Ar atmosphere as well as thermal analysis (DTA, DSC/TG) of contaminated PbI2 were carried out to characterise the influence of the H-2 treatment on the resulting material purity. At the same time, a hygroscopic nature of PbI2 could be disproved, and new results on the controversially discussed thermal behaviour of solid, oxide-polluted PbI2 are presented. Effective measures for the avoidance of oxidic impurities during source material processing could be derived. Finally, the effectiveness of an H-2 treatment is confirmed by single crystal growth experiments using the Czochralski technique. PbI2 crystals with improved structural properties and, for the first time a reproducible predetermination of crystallographic orientation are shown. (C) 2015 Elsevier B.V. All rights reserved.