Microplastics harm human health. Therefore, the present study assessed the knowledge and attitude of university students towards reducing microplastic use and examined their zero-waste behaviors. Our results lay the foundation for program development aimed at promoting zero-waste activities. The study was conducted from August 20, 2021, to September 10, 2021, including students at a university in G metropolitan city. Questions were developed to verify how the use of disposables and the knowledge, attitude, and behaviors related to zero-waste were affected after the COVID-19 pandemic. A survey was conducted with 197 students, and the data of 196 students were analyzed. Family type (β=0.146, p=0.042) and usage of disposables (β=0.158, p=0.049) were the factors affecting zero-waste behavior in Model 1. In Model 2, which included the subcategory of zero-waste knowledge, the health effects of microplastics (β=0.197, p=0.008) and environmental preservation (β=0.236, p=0.001) were significant factors. In Model 3, which included the subcategory of zero-waste attitude, the health effects of microplastics (β=0.149, p=0.016), use of eco-friendly products (β=0.342, p<0.001), and environmental preservation (β=0.317, p<.001) were significant factors. Therefore, additional studies and education on the health effects of microplastics are warranted, and suitable alternatives for disposables must be developed.