Plainview Elementary School which was the former Cadiz Annex became a separate unit effective November 3, 1964 with six pioneer teachers, (Miss Veneranda Barrion, Miss Carolina Caberte, Miss Ester Edralin, Miss Francisca Samson, Miss Estela Tasipit) and seven classes under the supervision of the teacher-in-charge, Mrs. Lydia Javier, now a retired district supervisor. The school building in the Cadiz compound was situated in the corner of Barangka Drive and San Rafael St. There were three rented classrooms in the compound, two rooms on the M. Cruz St., and at the Abando Annex. The start was really difficult and several problems especially the school needs were met and solved with the help of the P.T.A., the barrio council and the municipal council.

In 1965-1966, due to increasing population, the owner of the school building acceded to the request to build more rooms. The school year 1966—1967 was fruitful for the school. The municipal council accepted the donation of Ortigas & Co. Ltd. for the school site with 3,390 sq. meters.

As years went on, Plainview Primary School, continued to be growing institution with its increasing number of pupils and teachers. More classes were organized which made it become a complete elementary school.

In the early 70’s a three-room one-storey Marcos type building was built in the newly acquired site as an annex building. After some years, with the joint efforts of the new set of PTA officers of the school, two army type school buildings were constructed besides the Marcos type building. This San Joaquin annex finally became the main building when the two-storey Rodriquez type school building was erected in this place in 1975 leaving the rented buildings behind as annexes. In 1977, Mandaluyong was integrated with the division of Quezon City.

After several years of existence, the Marcos type and Army type school buildings were demolished to give way to standard school buildings. Later in 1994, as the City of Mandaluyong is recognized as a new division more buildings were built for Plainview Elementary School- The Gonzales Type Building 1 & 2. The demolition of Rodriquez type then followed and is replaced by a twelve-room three-storey Neptali Gonzales School building which now stands firmly with forty three teachers which compose the teaching force and with one thousand six hundred sixty nine (1,669) pupils enrolled in 36 classes (Kinder to Grade VI) coming from different barangays – Plainview, San Jose, Hulo and Addition Hills. Improvement still going on with the construction of the new four-storey, sixteen rooms Gonzales Building 3.

In August, 2014 the new four-storey with 16 classrooms (Gonzales Building 3) with an extension of 4 additional classrooms were completed. And at this point in time is the on doing construction of the school covered court quadrangle.

Plainview Elementary School improved tremendously through the years in academic as well as in extra-curricular activities under the supervision of a row of effective school Heads: