Drawing from the socio-cultural theory of Vygotsky, this study compared the academic performance gains scores of pupils in a Keypad Response Technology (KRT) class with those in two other pedagogies to determine the learners' language proficiency level in ESL classroom. A sample of 99 Nigerian primary six pupils participated in the study. Exploring quasi-experimental non-equivalent pre-test post-test control group design, data were collected through English Language Listening Tests and English Language Speaking Tests. Data analysis involved descriptive and inferential statistics such as t-test, Pearson Product Moment Correlation and Analysis of variance. The outcome of the study revealed a significant difference in the gain scores between low and high pre-test scorers across the groups. While a significant negative linear relationship exists between the pre-test scores and gain scores of pupils in the KRT and communicative approach groups, no significant linear relationship was found in the control group. The results also showed that there was a significant difference in the gain scores of pupils from one group to another with pupils in the KRT group having the highest gains. In view of its findings, the study recommended the use of KRT in ESL classroom as a way of enhancing Nigerian pupils' proficiency in English language. (Contains 8 tables and 4 figures.)