The school has a little over 1000 students[3] and the current administration includes Principal, Mr. Ricardo Hinojosa, Assistant Principals, Mr. Jason Acosta, and Ms. Michelle Guerra [1] Mercedes High School was originally located at 837 S Ohio St. and a second high school was built directly across the street and used until the present-day campus was built and opened in 1967.

The old high school is now part of Mercedes Early College Academy.

In 2002 a new complex was added to the southeast part of the school called the Career and Technical Education Unit.

In 2010, MHS plans to open new Physics labs located just outside the east and west I-halls and a new P.E.

Mercedes High School's notable accomplishments include their division I boys soccer team winning their division's region final against Westlake High School in 2007, where they won 2-1.