This study investigated the effect of providing students with the objectives of a lesson before the lesson delivery on their achievement at the end of the lesson. Two hypotheses were formulated to guide the study. The quasi-experimental pretest-posttest-control group design was used, with a total of 4 groups. All four groups were taught the same lessons using the same materials and methods. Three of the groups were shown objectives at various time intervals before the lesson, while 4th group was taught without prior knowledge of behaviour objectives. The test instruments (Biology Achievement Test) consisted of 50 multiple choice objective-reference questions, that was administered before the commencement of the teaching as pretest and after completion of the teaching as post-test. The data collected was analyzed by Analysis of Covariance (ANCOVA) and the Schefe's Pairwise comparison. The results indicated a significant effect at 0.05 alpha levels. The implications are discussed and recommendations made. (Contains 3 tables.)