The study investigated the relative effectiveness of generative learning strategy on students’ academic achievement in secondary school Biology. The research design adopted for the study was pre-test, post-test control group quasi-experimental with a 2 x 2 factorial matrix. The groups were crossed with gender as moderating variable to determine its effect on students’ academic achievement. Seventy-six students (76) in the intact classes but purposively drawn from two schools that met a set of criteria constituted the experiment. The research instrument was a 30-item multiple choice test named Biology Achievement Test (BAT) subjected to validity and reliability tests, the test-retest reliability co-efficient yielded 0.78. The data collected were analysed with both descriptive and inferential statistics and the results showed significant main effect of the strategy on students’ academic achievement in senior secondary school Biology. It further revealed that the students exposed to the Generative Learning Strategy (GLS) achieved higher post-test mean achievement score compared to their counterparts exposed to the conventional method. It was recommended among others that the strategy should be integrated into teacher education programme to allow would-be teachers to have adequate understanding and knowledge of its use.