Effects of Jigsaw and Geoboard Instructional Strategies on geometry Students' Achievements in Delta State was investigated in this study. Two research questions and two hypotheses were formulated to guide this study. The study adopted the quasi-experimental (non- randomized, pre-test, post-test, planned variation) design. The population of the study consisted of 18,879 SSII mathematics students in 435 public secondary schools in Delta State. The sample for the study consisted of 289 SSII students drawn from six public mixed secondary schools, using simple random sampling. Two from each of the three Senatorial Districts of the state. Instrumentation for the study was done with a Geometry Achievement Test (GAT), Data obtained from the instruments were analyzed using: mean, standard deviation, T-test, Analysis of Variance (ANOVA), Findings from the results showed that Jigsaw teaching, Geoboard strategy and Lecture method have significant effects on students achievement, in favour of Jigsaw teaching and Geoboard strategy. Based on the findings of this study, it was recommended that mathematics teachers in secondary Schools should adopt a better method of teaching mathematics (such as Jigsaw teaching and Geoboard strategy), to enhance students involvement in the teaching/learning process, as this will inturn result in better academic achievement by the students. Also, Government, on its part, should provide more funding and infrastructures to schools, so that there will be enough labs and instructional materials to engage students in task-base teaching methods.