Purpose: This study aims to investigate the listening effort made by young children in real classrooms during a prolonged speech reception task in the presence of background noise. Method: The experiment was proposed to 117 typically developing kindergarten and primary school pupils, aged 5-7 years old. An ecological experimental approach was followed, and speech-in-noise tests were presented in the classrooms to groups made up of the whole class. The speech material of the Word Intelligibility by Picture Identification Test in the Italian language (Arslan, Genovese, Orzan, & Turrini, 1997) was presented in 2 listening conditions (quiet classroom [no noise added] and working classroom [with stationary noise]) and was repeated twice during the experiment. Data on the number of correctly recognized words and the single-task response time (RT) were collected; the quantity of the latter was considered informative on listening effort. Results: It was found that when background noise was present, the pupils' performance decreased, and greater RTs were required compared to the "quiet classroom" condition. When the RTs were analyzed over the course of the experiment, there were no changes in the quiet condition, whereas in the working classroom, a significant increase was found for the 6- and 7-year-old pupils. On the contrary, the youngest pupils (5-year-olds) showed a decrease in the RT results over the test repetitions. Conclusions: The RT measured with a single-task paradigm was found to be a viable approach for investigating the listening effort in 6- to 7-year-old pupils. For this age range, the metric was sensitive to changes both in the listening conditions and within the same listening condition across the time of exposure. More research is needed to assess the feasibility of the experimental paradigm with the 5-year-old children.