This study investigated the Effect of Concrete Manipulative Approach on Attitude, Retention and Performance in Geometry among Junior Secondary School Students in Benue State, Nigeria. Quasi-experimental research design was used for the study. The total population of the study consisted of 6230 Junior Secondary School Two Students in Benue State, Nigeria. A sample of 211 students was drawn from the population for the study using a stratified proportionate random sampling technique. The instruments used to collect data were: Students' Geometry Attitude Questionnaire, Geometry Performance Test and the Instructional Instrument (Lesson Plans).The Questionnaire and the test instruments were validated by three experts and had a reliability of coefficient of 0.90 and 0.71 respectively. Five research questions were raised and five hypotheses were formulated to guide the study. The research questions were answered using the mean and standard deviation while the hypotheses were tested at 0.05 level of significance using Mann-Whitney U-test and t-test statistical tools. The results of this study indicated that (1) Students' attitude was rated positive in the Geometry concepts taught due to the use of Concrete Manipulative Approach. (2) Concrete Manipulative Approach was not gender bias in attitude formation. (3) The Concrete Manipulative Approach improved the performance of students taught Geometry concepts in Mathematics. (4) Female students exposed to the Concrete Manipulative Approach, performed equally with their males counterparts. (5) The retention ability of students exposed to Concrete Manipulative Approach was found to be better than that of the students' exposed to the Conventional Lecture Method. Based on the findings from this study, it was recommended that:(1) The Concrete Manipulative Approach be used by Students of Geometry in learning as it helped to form positive attitude inlearning Geometry. (2) It was also recommended that the Concrete Manipulative Approach be used by Teachers of Mathematics, as the use of it aid students to retain much of what was learnt. (3) It was recommended that the Concrete Manipulative Approach be used to teach Junior Secondary School Students in order to clear the beliefs that the study of Geometry is masculine. (4) It was also recommended that Concrete Manipulative Approach be incorporatedin the juniorsecondary school curricular.