The study investigated the Effect of Socialist Constructivist teaching strategy on Attitude, Performance and Retention in Algebra among Junior Secondary School Students in Kogi State, Nigeria. The study employed Quasi - experimental and control pre-test and post-test group design. The population comprised all the Junior Secondary School students in Kogi State during 2017/2018 academic session and was 29,433 (14,973 male and 14,460 female). JSS three students were used as the research sample. Multi-stage random sampling technique was used to select a sample size of 169 students (77 male and 92 female) from 8,464 JSS three students (4193 male and 4271 female). two educational zones were selected from eight in Kogi State. Among the mixed-gender secondary schools in selected educational zone, two were randomly chosen for the study. At the secondary school stage, an arm of JSS three was randomly chosen and the total number of students involved was 169 that served as the research sample In the chosen two secondary school in each educational zone, one was meant for experimental group and the other for control group by randomization. Four instruments namely Algebra Performance Test A, Algebra Performance Test B, Algebra Retention Test and Algebraic Attitude Questionnaire Scale were used to collect data for the research. The instruments were used respectively for pre-test, post-test, retention ability and attitudinal change. Algebra Performance Test A, Algebra Performance Test B and Algebra Retention Test consisted of forty-multiple choice questions on algebra content with five options (a, b, c, d, e.). The Algebra content covered included simplification of algebraic expressions, expansion of algebraic expressions, factors and factorization of algebraic expressions, simple equations and world problems on simple equations. Algebraic Attitude Questionnaire Scale consisted of twenty items with four options (Strongly Agree, Agree, Disagree, and Strongly Disagree) in order to elicit students‟ attitude towards Algebra. 5Es (Engage, Explore, Explain, Elaborate, Evaluate was injected into the study in order to boost socialist constructivist teaching strategy. Test-Retest using Pearson Product moment correlation was used to estimate the reliability coefficients of the instruments that measured performance and retention while Split-halves method using Spearman rank order Correlation Coefficient was used for Attitudinal Scale. The respective reliability coefficients were 0.80 and 0.97 Six research questions and six null hypotheses were analysed in the study. t-test for independent samples and Mann Whitney at significance level of 0.05 were used to carry out the data analyses. The results indicated significant differences in the mean performance, retention and attitudinal change in favour of experimental group. But under the experimental group there were no significance means difference between male and female in terms of attitudinal change, performance and retention. It is recommended that students should constantly practise and revise their algebra lessons, teachers should employ different forms of socialist constructivist teaching strategy in the classroom and schools should encourage seminars, workshops and in-service training for teachers to update their mathematical knowledge. Schools should give prize to outshining mathematics student and should encourage the dull ones not to give up.