Abstract Objective Lead orientation is a new degree of freedom with directional deep brain stimulation (DBS) leads. We investigated how prevalent deviations from the intended implantation direction are in a large patient cohort. Methods The Directional Orientation Detection (DiODe) algorithm to determine lead orientation from postoperative CT scans was implemented into the open-source Lead-DBS toolbox. Lead orientation was analysed in 100 consecutive patients (198 leads). Different anatomical targets and intraoperative setups were compared. Results Deviations of up to 90° from the intended implantation direction were observed. Deviations of more than 30° were seen in 42 % of the leads and deviations of more than 60° in about 11 % of the leads. Deviations were independent from the neuroanatomical target and the stereotactic frame but increased depending on which microdrive was used. Discussion Our results indicate that large deviations from the intended implantation direction are a common phenomenon in directional leads. Postoperative determination of lead orientation is thus mandatory for investigating directional DBS. Full Disclosures Till A. Dembek reports speaker honoraria from Medtronic and Boston Scientific. Mauritius Hoevels has nothing to disclose. Alexandra Hellerbach has nothing to disclose. Andreas Horn reports speaker honoraria from Medtronic. Jan Niklas Petry-Schmelzer reports travel grants from Boston Scientific. Jan Borggrefe has nothing to disclose. Jochen Wirths reports travel grants from Boston Scientific. Haidar Salimi-Dafsari reports honoraria from Medtronic and Boston Scientific. Michael T. Barbe reports grants from Medtronic and Boston Scientific. Veerle Visser-Vandewalle is a member of the advisory boards and reports consultancies for Medtronic, Boston Scientific and St Jude Medical. She received a grant from SAPIENS Steering Brain Stimulation. Harald Treuer has nothing to disclose.