During the development of a crystallization process for a peptide, two distinct crystal forms were observed; an anhydrous form and a hydrate form. The hydrate was more stable of the two forms under crystallization conditions. However, the anhydrous form provided a processing advantage due to better filtration characteristics, thereby reducing the downstream processing required for an acceptable quality peptide. The processing advantage was further enhanced by making spherical agglomerates of the anhydrous form. This was achieved by controlling the rate of desupersaturation during crystallization. Since the incoming peptide solution had inherently high supersaturation, controlling the rate of desupersaturation was critical to prevent precipitation of amorphous material. The effects of various crystallization parameters on desupersaturation rate were studied to design a robust process for making spherical agglomerates of the anhydrous form. The results of these studies and scale-up data for the process will be discussed.