The COVID-19 pandemic has drastically altered the dietary habits and preferences of the global population. Therefore, the aim of this study is to identify factors that influence customers’ restaurant dining behaviours and examine the most notable factors that influence the customers’ behaviours during and after the COVID-19 pandemic. This is because every patron would consider several matters before deciding to choose the type or location or restaurant they would like to eat at. Customers’ decisions are typically influenced by several variables and standards, including the quality of food, quality of service, physical environment, and facilities or amenities. This quantitative-research study has primarily targeted three states in the East Coast of Malaysia, namely Pahang, Terengganu, and Kelantan. The study has employed an online questionnaire to customers who have dined out at restaurants before and after the COVID-19 pandemic. A total of 405 participants have actively participated in the study and responded to all the questions in the online questionnaire. The findings of the study have indicated that food quality, service quality, restaurant environment, and facilities or amenities have a substantial impact on customer behaviour when dining out both during and after the COVID-19 pandemic.