The purpose of this study was to investigate the effectiveness of the advance organiser model (AOM) on students' academic achievement in learning work and energy. The design of the study was quasi-experimental pretest-posttest nonequivalent control groups. The total population of the study was 139 students of three sections in Endabaguna preparatory school in Tigray Region, Ethiopia. Two sections with equivalent means on the pretest were taken to participate in the study purposely and one section assigned as the experimental group and the other section assigned as the control group randomly. The experimental group was taught using the lesson plan based on the AOM, and the control group was taught using the lesson plan based on the conventional teaching method. Pretest and posttest were administered before and after the treatment, respectively. Independent sample t-test was used to analyse the data at the probability level of 0.05. The findings of the study showed that the AOM was more effective than the conventional teaching method with effect size of 0.49. This model was also effective to teach male and female students and objectives namely understanding and application. However, both methods were equally important to teach work and energy under the objective knowledge level.