This study sought for the effect of the use of behavioural objectives on Senior Secondary students' academic performance in Mathematics in Omu-Aran, Kwara South Senatorial District Area of Kwara State, Nigeria. The target population for the study comprised Senior Secondary Two (SS II) students in Omu-Aran town. Purposive sampling technique was employed to select 179 students for the study. A quasi-experimental, non-randomized, non-equivalent, pre-test, post-test control group involving a 2 x 3 factorial design was employed as research design. The dependent variable was the Mathematics Academic Performance Test (MAPT) administered. The independent variables were the instructional strategy and the scoring levels. The test scores were analyzed using mean scores, standard deviations, t-test and Analysis of Covariance on the two null hypotheses formulated. An alpha level of 0.05 was used to determine the significant level. Findings from the study showed that the experimental group significantly performed better in Mathematics Academic Performance Test than the control group. Based on this finding, it was recommended among others that teachers of Mathematics should always present the set behavioural objectives to the students prior to the lesson in order to enhance students' full participation in the lesson. Mathematics students should also be provided with academic counselling.