This paper reports a fast, sensitive pattern recognition method for determining the polymorphic quality of a solid drug substance, polymorph A, The pattern recognition method employed can discriminate between the desired polymorphic form of the drug substance and another undesired polymorph. In addition, it can reliably detect samples containing minor levels of the undesired polymorph. The method can also discriminate between the desired polymorph and other crystalline forms. Most significantly, this sensitive method has been successfully transferred to six other near-IR instruments without resorting to sophisticated multivariate calibration transfer strategies.