Giant unilamellar vesicles (GUVs) are an essential component of techniques used in the investigation of biophysical properties of e.g., lipid membranes, electrogenic transmembrane proteins, lipid raft formation, and lipid-DNA interactions. The Vesicle Prep Pro is an automated device for the preparation of these GUVs. The Vesicle Prep Pro offers a standardized and robust way to reliably and reproducibly generate GUVs of homogeneous size distribution with high yields.