Integrative learning assessment is a type of assessment that aims to combine students? learning from multiple subjects/disciplines into a single assessment. This study determined the level of validation and utilization of integrative assessment material as an authentic assessment tool in teaching Science. This was a quantitative research that utilized the Independent and Dependent (IV-DV) variables model. The data gathered were analyzed and treated using weighted mean and Pearson product-moment correlation. This study was conducted during the third quarter of the S.Y 2021-2022 to 60 Science teachers and experts and 80 students from the City Schools Division of Cabuyao. The teachers and experts answered a survey questionnaire on the validation and evaluation of the integrative assessment materials in Biology. The other group of respondents which are the students utilized the said materials by performing the tasks and activities which were rated by the teacher. They also answered a questionnaire to determine their perceptions toward the integrative assessment materials. Findings showed that the integrative assessment materials that were validated by the teachers and experts got a ?Very High? level of validation, which means that these materials can be used as authentic assessment tool in teaching Science. On the other hand, the students? level of perception also got? Very High? towards the integrative assessment materials which means that they perceived and find the materials very good and helpful in measuring their learnings. In relation to this, upon the utilization of these materials, the students achieved an ?Outstanding? level in their scores in terms of the performance tasks. However, there was no significant relationship between the level of perception of students and their performance scores. It was concluded that there were other factors attributed to their perceptions toward the materials and to their performance scores. Results from this study provide recommendations for future research.