Solid-state pharmaceutical chemistry encompasses a wide range of studies on pharmaceutical solids including (1) determination of the physical properties of polymorphs and solvates, (2) physical transformations between polymorphs and solvates, (3) chemical reactions in the solid state, and (4) solid-solid reactions which occur in pharmaceutical preparations. Recent advances in this field include improved understanding of crystallization processes, improved understanding of the need for characterization of polymorphs and solvates for both control and regulatory purposes, and a better understanding of the mechanisms of solid-state degradations and solid-solid reactions. This review will briefly describe recent advances in the following areas: (1) crystallization and the properties of crystals of pharmaceutical solids; (2) characterizations of crystal forms of drugs using solid-state NMR spectroscopy.