This study examined the Effects of Computer - Based Instruction on Retention and Performance in Algebraic Word Problemsamong Junior Secondary School Students in Kaduna State, Nigeria. The study was guided by four research questions and four hypotheses. The quasi experimental research design involving two groups (one experimental and the other control) was used. The population of the study comprised of junior secondary school two (JSS2) students of the public secondary schools in Kafanchan Educational Zone of Kaduna State. Two (2) coeducational schools were selected by the simple random sampling method as school for the research. Two intact classes were selected using the simple random sampling from the JSS2 arm from which 98 students participated as sample for the study (53 male and 45 female). Two instruments: Algebraic Word Problems Performance Test (AWPPT) and Algebraic Word Problems Retention Test (AWPRT) were used for data collection. The research hypotheses were analyzed using the t-test at P ≤ 0.05 level of significant by the aid of the computer software Statistical Packages for Social Sciences (SPSS version 21). The results obtained showed a significant difference in performance in favour of student exposed to the Computer Based Instruction (CBI). The results also revealed no significant difference in performance of male and female students when exposed to CBI. The result further revealed that the students exposed to CBI had better retention compared to their counterpart who were taught by the lecture method. However, the difference in retention of male and female students exposed to CBI was not significant. The study concludes that the CBI is effective in the teaching and learning of algebraic word problems in junior secondary schools and it is a gender friendly teaching method. Based on the findings the following recommendations were made: teachers should employ the CBI in the teaching of algebraic word problems in junior secondary schools to enhance students? performance. Workshops and seminars for mathematics teachers should be organized by the Ministry of Education for each educational zone in Kaduna State on the use of CBI.