Usability is one of the aspects that need to be highlighted to determine the quality of an information system (IS). Usable system will ensure the users' interests in using the system especially in education field. Previously, MobileSchool system has been developed for secondary schools communities including school administrators, teachers, students and parents. This paper presents the usability study of the system that was developed. This study involves 420 users as the respondents that consist of school administrators, teachers, students and parents from three secondary schools in Perak state of Malaysia. This study also involves the questionnaire instrument where the questions have been asked to measure seven usability elements including visibility of system practice, learner control and freedom, consistency and loyalty to standard, error prevention, flexibility and efficiency of use, minimize information on screen and design for small screen. Two analyses of descriptive statistics have been used to conclude the usability level of MobileSchool system; mean and frequency in the form of percentage. The result for both analyses shows that MobileSchool system has passed the usability requirements. © 2014 IEEE.