Food waste is the largest component of solid waste in Penang. Understanding the composition and sources of food waste is crucial to reduce and manage wasted food efficiently. As most of the studies were focused on commercial restaurants that mainly studied the waste pattern from the society, in this study, the focus is on a tertiary education institution and food waste was collected from five food premises from the campus of Universiti Sains Malaysia, Penang during the semester break and at the beginning of the semester. The waste was quantitatively investigated and compositionally analysed according to two categories: preparation and customer plate waste. Within each category, avoidable and non-avoidable waste was identified, segregated, and measured. The weight among the groups was compared statistically, and the carbon dioxide emission also calculated based on the Defra factor. In general, preparatory waste was significantly higher than the customer plate waste for both semester break and at the beginning of the semester. The avoidable waste generated from customer plate waste at the beginning of the semester was significantly greater compared to the one during the semester break, and this might indicate wastage of food by the undergraduate students. The current study suggests that food waste arises differently in the aforementioned categories from the tertiary education institution and future research might focus on the works that support the engagement of food premises to identify the reasons for food waste within their facilities and appropriate measures to address the issues.