Previous research has shown that dialogic teacher talk not only supports students' understanding but also raises their interest. However, there is little, if any, research on the connection between dialogic talk and student interest in classroom situations. To investigate this connection, we collected video observations and experience sampling data. In total, 87 middle school students aged 14 to 16 participated in the study. Data were collected from the classes of six science teachers, and three lessons were video recorded in each teacher's classroom. During the lessons, students were asked several times to express their interest in the situation through the experience sampling method (ESM). The measurements took place in situations where the teacher either talked with the students or talked to the whole group of students. The talk situations were categorised as dialogic or non-dialogic, based on the video recording. On a five-point scale of interest, the median value was 3.3 in non-dialogic talk situations and 3.5 in dialogic talk situations. We hypothesised that students' interest would be higher in dialogic talk situations than in non-dialogic talk situations. The hypothesis was tested with a related samples Wilcoxon signed rank test, and the results supported the hypothesis (Z = -2.62; p < 0.05). The results suggest that dialogic talk may trigger students' interest in science learning.