Studies suggest that the learning environment can act as a third teacher in contributing towards student academic success. A variable within the physical learning environment that has received little attention in the literature is the interior lighting. Because of budget constraints and age, most American public school classrooms have fluorescent lighting fixtures installed. A new lighting technology, Light Emitting Diodes (LEDs), is becoming popular in commercial facilities across the United States because of energy efficiency. Previous research has demonstrated that lighting influences adult worker productivity and mood in a workplace. However, because children process stimuli faster, it is unknown whether LED lighting would have the same influence in a learning environment. Researchers hypothesise that students display more engaged behaviours in classrooms lit with LEDs as compared with fluorescent lighting fixtures. The current study tested this hypothesis by observing child engagement behaviours in a pre-K classroom under LED lighting and fluorescent lighting fixtures to compare differences. Students displayed more engaged behaviours under the LED lighting condition.