Portola Middle School is the city's only middle school and is one of six middle schools in the West Contra Costa Unified School District. The existing school building, built in 1949, was deemed earthquake unsafe, and the school board decided it couldn't be fixed or rebuilt on the existing site because it is located on a landslide-prone slope that would be unsafe in a major quake. After much debate, the board decided to convert Castro Elementary School site into the new middle school. Temporary classroom buildings were constructed on the lower portion of Portola site in 2010 to be used while the new school is built on the Castro site. The old Portola buildings were torn down in 2012.
The school's 2011-12 School Account Report Card can be accessed here. It lists enrollment as 497.