Monitoring weight gains in feedlot cattle using a crush is time consuming and may impact cattle performance through increased handling and time spent away from the pen. Methods for in pen weighing around a water point in feedlots have been developed (Vytelle 2022) but there may be opportunity to use other more portable systems in feedlot pens. The Optiweigh system (Optiweigh 2022) has been developed for in paddock weighing of cattle using a stand-alone unit with a supplement block as an attractant and satellite-based telemetry for data communication. When cattle access the supplement in the Optiweigh, by placing their front feet on a platform, a partial body weight is recorded and converted to a full body weight. This project used an Optiweigh in a feedlot pen to determine whether feedlot cattle would utilise it when a complete diet was already on offer and if it could be used to accurately monitor weight gain over a feeding period