Information systems are applied to a range of activities by organizations to improve efficiency and effectiveness. They are used in almost all industries, including manufacturing, health, and education. Therefore, organizations must measure and evaluate the usability of their systems to get the most value from the systems. One of the most reliable evaluation scales that can measure the usability of the systems is the system usability scale (SUS) which was used in this study to evaluate the usability of Blackboard at universities in Saudi Arabia. This study showed that Blackboard as LMS had a high SUS score when it was used at Saudi Universities. Indeed, the current study revealed that Blackboard could be used in teaching effectively. Furthermore, the current research findings show that students have higher SUS scores than lecturers, which means they can easily use Blackboard. It is also recommended that lecturers receive more training on Blackboard.