The study investigated whether students’ achievement in Basic Science in Basic Education Certificate Examination (BECE) is a predictor of their performance in Biology in Senior Secondary Certificate Examination (SSCE). Three research questions and three null hypotheses guided the study. Expost facto research design was adopted for the study. The students’ scores in Basic Science in BECE in 2010 and students’ scores in Biology in SSCE in 2013 were used. Regression analysis was used to answer the research questions as well as to test the null hypotheses at 0.05 level of significance. The findings revealed that students’ achievement in Basic Science in BECE is a moderate predictor of their performance in Biology in SSCE (β = 17.5%). The results also showed that the achievement of male students in Basic Science in BECE significantly predicts their performance in Biology in SSCE (β = 19.8%). It was also found that the achievement of female students in Basic Science in BECE significantly predicts their performance in Biology in SSCE (β = 15.8%). It was recommended among others that placement of students into science classes especially Biology classes at the senior secondary school level of Education should be strictly based on the achievement of 50% and above in Basic Science in BECE. There should be a strong and reliable counseling unit in the schools with counselors to help handle the issue of placement in case any issue of interest arise either from the parent or student. Workshops, seminars and symposia should be organized by Ministry of Education regularly for science teachers to update their knowledge to enable them teach Basic Science effectively.