Abstract There appears to be a general, global trend of many students not taking chemistry related courses at post-secondary institutions, while the academic performance of the subject at secondary level is on the decline. Addressing the performance and unpopularity gaps of the subject requires an exploration of effective pedagogical practices. One critical objective of a chemistry teacher is to create an active learning environment. However, due to insufficient research, relatively little is known about the concept and role of class talk interaction in enhancing learners’ engagement and inquiry-related curiosity. To address the gap, the current study explored the effect of class talk interaction on students’ learning outcomes in chemistry. The study adopted a descriptive survey design. The study involved a sample of 384 students and 30 teachers, drawn from 30 public secondary schools in Murang’a County, Kenya. Data was collected through validated instruments which included students’ questionnaire, interview schedule, observation checklists and also a Chemistry achievement test. Descriptive statistics revealed that learners were very poor in utilizing class talk interaction, in comparison with teachers who were rated above average. Further, inferential statistics involving one way ANOVA revealed that there was a statistically significant effect of class talk on learning outcomes, while simple regression revealed that class talk is a strong predictor of learning outcomes. These results indicate a need for policy interventions aimed at achieving meaningful instructional class talk interaction between teachers and students as a way of improving learning outcomes.