Studies have shown that performance feedback provided by teachers can communicate mindset messages to students and subsequently impact students’ performance. We sought to examine whether non-feedback related comments could also influence students’ mindsets and performance. We utilized a sample of undergraduate students enrolled in a research pool (n = 106) and compared their mindset and quiz scores after receiving a statistics lesson under one of three conditions. In two conditions the instructor introduced the lesson making comments that communicated either a fixed or growth mindset. A third condition served as a control. Students receiving growth comments moved towards growth mindset beliefs more so than those who received fixed mindset comments and had higher quiz scores when compared to the control group. These results provide early evidence that even non-feedback related comments can influence students’ mindsets and performance. We discuss implications for teaching, teacher training and future research.