This study investigated the effect of flipped classroom model on the academic achievement and retention of upper basic learners in Basic Science and Technology (BST) in Benue State, with a focus on gender variable. Four research questions and four hypotheses guided the study. A pretest post-test control group, non-equivalent quasi-experimental design was used for the study. The sample of 120 learners was drawn from the population of 3,767 Basic 8 (JSS 2) learners from Makurdi Local Government. Intact classes were randomly selected and assigned to experimental and control groups. Basic Science and Technology Achievement Test (BSTAT) and the Basic Science and Technology Retention Test (BSTRT) researcher-design instrument were used for data collection. The BSTAT items of the instrument were subjected to face and content validation. The reliability of the instrument was established using Kudar-Richarson formula 20 (K-R20). The reliability coefficient of the instrument was found to be 0.78. A flipped classroom model lesson plan was used for classroom instruction in the experimental group while the control group used lesson plan on lecture method for instruction. The research questions were answered using mean and standard deviation, while the hypotheses were tested at 0.05 alpha level of significance using Analysis of Covariance (ANCOVA). The findings from the study revealed that learners taught using the flipped classroom model significantly outperformed those in the control group in both academic achievement and retention of BST concepts. Furthermore, while both male and female learners in the experimental group showed improved performance, no statistically significant gender differences were observed in the outcomes, suggesting that the flipped classroom benefitted learners regardless of gender. The findings underscored the effectiveness of the flipped classroom model in promoting deeper understanding and long-term retention of scientific concepts in BST. The study recommends that educators adopt flipped learning strategies in science instruction and provides evidence that gender does not moderate the positive effects of this pedagogical approach.