As the first and oldest high school in Mariveles, Llamas Memorial Institute opened in 1951 as Mariveles Institute. The school was founded by and began in the home of Tia Elisa Llamas who accepted chicken, piglets, eggs and other farm products for tuition to ensure the education of the children in poor families. The school grew slowly.

Tia Elisa stood firm in her conviction and continued her efforts of providing an education to the children of poor families. Her efforts were rewarded. By the mid 1980’s, enrollment had swelled to over 1000 students. Subsequently, the name of the school was changed to Llamas Memorial Institute in honor of Tia Elisa’s brother, World War II era Bataan Congressman honorable Antonio G. Llamas. He was killed by the Japanese in the battle of Manila, February–March 1945.

When Tia Elisa became disabled, she turned the school responsibilities over to her niece, Nenita Llamas Sesbrefio, who was the daughter of her brother, the Congressman. After Tia Elisa passed away in 1985, Mrs. Luningning Yraola Pidong became the school Principal.

On November 23, 2011, during the week-long celebration of the school’s foundation, the Municipal Government of Mariveles bestowed Llamas Memorial Institute the legal and honorary title of being the first “Municipal Historical Landmark” among all institutions and places in the town. The title is not simply about the status it bestows but rather, is all about the responsibilities it places on the shoulders of all stakeholders: government and school administrators, teachers and staff, parents and students, including the alumni all bearing significant roles for the continuous well-being and the future of the institution. The generations to come will always remember Llamas Memorial Institute as a treasure of the community bearing significant space in our hearts forever.

In the last quarter of 2017, Mr. Rustico Villanueva Recto Jr., a civic leader from Lipa City knew of the struggles that LMI was facing. The Sesbrefio family offered the school to Mr. Recto and it did not take too long before the latter accepted the offer. Mr. Recto has high hopes that his team could help LMI reach new milestones that would eventually benefit the youth of Mariveles, Bataan. There was a transitional operation during the school year 2017–2018 and in the following year, LMI was fully managed by LMI Integrated Formation and Education Inc. (LIFE Inc.), with Mr. Arnold Capuloy as its President.

During the transition year, LIFE Inc. made possible the construction of 6 new air-conditioned classrooms, renovation of 8 air-conditioned classrooms, ICT Hub, and construction of a 3-storey building with 8 classrooms, 1 TLE Laboratory, clinic, and canteen. The Elementary Department was opened in 2019 that necessitated the expansion of the campus. On September 8, 2020, a 3-hectare land was purchased at Barangay San Isidro, Mariveles, which will become the future site of LMI’s extension campus. The groundbreaking of the new campus was held on September 8, 2025.

In 2026, the Board of Directors of LIFE, Inc. decided to give the school a name that will create a strong brand and identity along with continuity, and mission. By the end of SY 2025-2026, the Board adopted the name LIFE Institute Mariveles to strengthen an identity that is already lived and understood. During the launching of the 75th Anniversary celebration of the school, the new name and school seal were presented to the alumni, students, teachers, and parents.

On its 75th year, the school that was known as MI, LMI, and LIFE became known as LIFE Institute Mariveles. This name speaks well of the school’s purpose – Education for life, Formation of mind, heart, and character, and to denote continuity with renewal.