As of 2015, there are over 27,000 middle school students enrolled in the Polk County School District. Although this number represents grades six through eight, some schools can have different grades in middle school, and small private schools don't always distinguish between elementary, middle and high school.
There are 39 middle schools in the Polk County School District. The average school has 600 to 700 students, although some schools have far less, including Lakeland Montessori Middle at the Polk Museum of Art. This middle school only contains grades seven and eight with a total population of about 50 students. The Lakeland Highlands Middle School has over 1,200 students.