An efficient and reliable approach to discover new pharmaceutical cocrystals in the early development stage is proposed and used to develop cocrystals of piracetam with some aliphatic diacids. A 1: 1 cocrystal of piracetam and glutaric acid was screened by a mechanochemical method and identified by powder X-ray diffraction and differential scanning calorimetry. Followed by solution crystallization, this cocrystal was reproduced. To better understand the mechanism of cocrystal formation in solution crystallization, process analytical technologies including focused beam reflectance measurement, attenuated total reflectance-Fourier transform infrared, and particle vision measurement were applied to investigate the cocrystallization process of piracetam with glutaric acid. The mechanism of cocrystal formation during solution-mediated phase transformation is discussed in detail.