Polymorphism changes the effectiveness of a drug, and it is often a problem in drug development. Different polymorphs often have different thermodynamic stabilities in a solvent. One method to determine the thermodynamic stability is by observing the solid-liquid interfacial energy of the polymorphs. In this study, the solid-liquid interface of paracetamol (p-Hydroxyacetanilide) crystals in water is investigated using molecular dynamics simulation. Monoclinic (form I) and orthorhombic (form II) are the known polymorphs of paracetamol. The potential energies of the crystal-water interface for these polymorphs are calculated and the interfacial energies of the ( ), ( ), ( ), ( ), ( ), and ( ) faces of each crystal structure are examined to study the relative interaction between the crystal and water at different crystal faces.