The Basic Technology teachers in the JSS level do not seem to be aware of the activity-based instructional methods such as co-operative learning strategies as school instructions remain teacher-dominated. In order to popularize the co-operative learning methods in Basic Technology, this study examined the effect of co-operative learning methods (Learning Together (LT) and Jigsaw group (JG) as well as sex effect on Basic Technology achievement in the JSS level. Two hypotheses were tested, and the study employed a three-way factorial non randomized control group, pre-test, post test design.