Culminating the MESA student experience each year is MESA Day. MESA Day is a regional event that engages students in STEM-based MESA competitions to test their design skills and math acuity. MESA projects provide the groundwork for the competitions that are offered during the event. Competitions include: Balsawood Glider, Bridge, Model Science, Mousetrap Car, Oral Presentation, Packaged Egg Drop, Prosthetic Arm, and Rube Goldberg Device.  Competitions will be held in and around the E-QUAD on the USC Campus

The LA Metro Region's MESA Day includes students from the USC, UCLA, Cal State Los Angeles and Long Beach State MESA Centers. Each year, at Junior MESA Day, about 400 middle students converge on one of the LA Metro Region Campuses. Over 600 high school students participate in Senior MESA Day. In addition to participating in the competitions, MESA students learn about STEM through interactive exhibits, hands-on activities and workshops.