Several crystal forms of valacyclovir hydrochloride, including two anhydrous and three hydrates, were investigated in this study. At the same time, a new hemihydrate of valacyclovir hydrochloride was first discovered and its properties were characterized by PXRD, TGA, DSC, and Raman in this study. The hemihydrate shows a distinctive PXRD pattern and a melting point of 209 °C with a water weight loss of 2.42% from the thermal analysis. The Raman spectra show a few distinctive peaks in the region of 1250–1400 cm−1 due to different crystal forms. The thermostability testing suggests it is a stable crystal form and remain the same for several months under high temperature and humidity. All these crystal forms show good dissolubility in the water at room temperature with excess 100 mg/mL.