This research compared the performance of primary pupils in the class five after teaching using Kanuri and English languages to teach lower Basic Science and Technology Concepts among pupils in Maiduguri Metropolis, Nigeria. It explored the impact of using the learners' mother tongue (Kanuri) and second language (English) as languages for teaching and learning science at the lower Basic Science and Technology class. The study additionally explores the influence of gender on academic performance of pupils when taught in their mother tongue. The population from which the sample for this study was drawn are primary five pupils of the five model primary schools in Maiduguri Metropolis with a total population of 2371 pupils. Two model primary schools were purposively sampled on their suitability for the study. The sample size is 95 primary five pupils in the selected schools made up of 55 boys and 40 girls. The research design is quasi-experimental. For data collection, Basic Science and Technology Achievement Test (BSTAT) was used. A pretest, post-test, post-posttest was carried out to determine the level of achievement and retention after teaching using Kanuri Language and English. Four research questions and four research hypotheses were stated and tested. The hypotheses formulated tested whether Kanuri and English, as media of instruction, and gender have impact on academic performance and retention when Basic Science and Technology concepts are taught to primary five pupils in the study area. The hypotheses were tested using t-test of significance at P ≤0.05. The research findings showed, among others, that pupils performed better and had higher retention when taught concepts in Basic Science and Technology using Kanuri language than when taught using English language. The study also showed that gender has no impact on performance and retention when pupils were taught the same concepts of Basic Science and Technology in Kanuri. The study recommends that Kanuri should be adopted as the language of instruction at lower basic levels for teaching Basic Science and Technology in the area of this study, since it is the local language of the area. It also recommends for the training of teachers and the development of suitable teaching resources to create the enabling environment for learning to take place effectively.