The study examined the effectiveness of developed instructional module on the enhancement of learners’ academic achievements specifically this current situation of COVID-19 pandemic under distance learning delivery modalities. This instructional module in Physics was personally developed by the researcher and intended to used in teaching-learning process in Senior High School under the Department of Education. The participants of the study are the grade 12 SHS students at Aliaga National High School into two groups –the controlled and experimental. The parameters are the content knowledge, alignment to learning competencies, learning tasks, assessment method, design course, friendliness and timeliness. To examine the effectiveness, the experimental research designed was employed. The following findings were made: the mean pre-test scores of two groups had 5.40 and 5.33 which means almost the same while the post-test mean scores of controlled group had 14.40 and experimental group had 17.80 which means the mean scores of experimental group were higher than the mean scores of the controlled groups. The pretest of two groups of participants had value of 14.976 with significant value of .000 and found out “not significant” while the post-test had value of 14.976 with significant value of .000 and interpreted as “significant” therefore the developed instructional module in Physics found “effective” and had impact to students’ academic performance. On the assessment made on the effectiveness of developed instructional module in Physics the overall weighted mean got 3.77 with an interpretation of “Very Satisfactory”. Continuous development and enhance of instructional module is recommended.