This study examined the effects of biology practical activities on the academic performance of students that were taught biology in Senior Secondary Schools of Adamawa State. The study had four objectives which included to: compare the pre-test and post-test performances of students taught biology using practical activities in Senior Secondary Schools in Adamawa State; determine the level of retention of students taught biology concepts using practical activities and lecture method in senior secondary schools in Adamawa state; compare the mean performance score of rural and urban students taught biology using practical activities and lecture method in senior secondary schools in Adamawa state and compare the mean performance of students taught biology practical activities using real specimen and those taught using chart among senior secondary school students in Adamawa state. In line with the objective four research questions were raised and four hypotheses postulated. The study used a quasi-experimental research design. The population of the study consisted of all 89,196 SS2 biology students in Adamawa state spread across 288 public secondary schools. From this, a sample of one hundred and sixty (160)students drawn from four different schools with two from urban and two from rural areas. The research instrument used for this study was Biology Practical Test (BPT), which consisted of items grouped into three sections (A, B and C) They were all practical skills test item sconsisting of Essay practical questions on different topics. Section „A,? classification of living things, Section „B,? Classification of fruits and reproduction in flowering plants, Section „C,? Nutrition in animals and digestion in birds. Mean and standard deviation were used to analyze the data while Independent t-test statistics was used to test the hypotheses at 0.05 level of significance. Findings revealed that: the post-test performance of students taught biology using practical activities was significantly higher than their pre-test performance; students taught biology concepts using practical activities had significantly higher retention level than those taught using lecture method. The used of practical activities significantly enhance academic performance in both rural and urban schools. Students taught biology using real specimen performed significantly better than those taught biology using charts. Hence, the study concluded thatpractical activities produced students with significantly higher academic performance in biology. It was therefore, recommended among others that the use of practical activities in teaching biology should be encouraged in all secondary schools that offer biology in Adamawa state and other states in Nigeria.