This research extends the Theory of Planned Behavior (TPB) in explaining the Millennials’ (born between 1980 and 2000) intention towards using environmental-friendly drinking straws. In order to meet the objectives of the study, this research was conducted to 252 millennial respondents in the city of Jakarta and its surrounding vicinities. The findings from this study shows that environmental attitude, personal norms and social norms do influence the behavioral intention. Meanwhile, the findings indicate that there is not enough evidence to support the hypothesis that assert perceived environmental knowledge affects the usage intention. Our findings suggest a more nuanced view of the Millennials’ pro-environmental behavior than is depicted in popular accounts.