Electrochemical deposition of the organic semiconductor perylene phenethylimide (PPEI) is reported. The deposition is based on neutralization of the unstable PPEI ions that are produced electrochemically during the deposition process. A mechanism for the deposition is suggested based on a comparison between depositions in the dark and under illumination. A thin insolating layer of PPEI is first formed followed by growth into long crystals via localized conductive points. The nature and the quantity of the conductive points are determined at the beginning of the deposition which was found to be the most sensitive part of the process.