Equipping individuals with sex-related information, motivation and behavioral skills is the main objective of sexuality education. It will enable the people especially the youth to avoid problems related to sexuality and to achieve sexual well-being aspects. This study evaluated the effectiveness of sexuality education integration among 100 students of Grade 10 Biology instruction in relation to student’s performance at Pinamungajan National High School. Quantitative and qualitative designs were used to determine the entry and exit knowledge of the students on sexuality education, looked into the pre and post-test performance of the students, the pre-post mean gain in integrating sexuality education, the module that was developed used for effective integration and the challenges met by the teacher in integrating sexuality education. The study was limited only to the Grade 10 students because reproductive system is being taught in Biology 10 instruction and it’s a good avenue for sexuality education integration. With the use of a researcher-made module in integrating sexuality education in reproductive system, the level of student’s awareness towards the cause and effects of early sexual activity and HIV spread increases for there was a significant difference between the pre-test and post-test mean gain of the students.The result of the evaluation of the integration indicates that sexuality education is a way forward towards enhanced Biology Curriculum Delivery. Since teenage pregnancy and HIV spread is rapidly increasing, there is a need now that teachers should start integrating sexuality education emphasizing teenage pregnancy and HIV spread to the students. This is one good intervention in delaying sexual activity, preventing them from the effects or risks caused by early sexual activity, help restore their values thus increase their self-efficacy towards decision making.