The surface area of the secondary explosive pentaerythritol tetranitrate (PETN) affects its initiation and performance. A decrease in the surface area, as well as morphology changes, in PETN has been observed during aging. Commercially, water is used in the production of PETN which suggests an uninvestigated stability control factor. In this article, single crystals of PETN were grown by solvent evaporation method from acetone at room temperature in absence and presence of different weight ratios of de-ionized water. The effect of presence of water in the starting solution of PETN on its thermodynamic properties was investigated using thermogravimetric analysis and differential scanning Calorimetry. The TGA study suggests an important role for water in manipulating thermodynamic parameters of PETN via the expected hydrogen bonding. The DSC results suggest the presence of bound water molecules as impurity in PETN single crystals. The data could be used to form PETN crystals with desired physical properties optimal for either storage or initiation. This study suggests that, in the equilibrium conditions, water could be used in a cheap, tunable, and precise manner to control the stability of PETN crystals against coarsening. (C) 2012 Elsevier B.V. All rights reserved.