Last week gobsmacked students at Stanford University, California, were given the surprise of their lives when the movie star interrupted a class on Maintaining Sustainable Building Projects to lecture them on environmentally friendly design.
The 33-year-old actress, who is best known for her roles in There's Something About Maryand Charlie's Angels, is not the first screen idol to be sucked in by the lure of the architect's office.
Earlier this year Hollywood heartthrob Brad Pitt was photographed working on Frank Gehry's controversial Hove scheme.
Back in May there were also rumours that Haydn Christensen of Star Warsfame was set to quit the movie business to train as an architect.
A champion of green causes, Diaz was given her first opportunity to teach design by her friend and internationally renowned eco-architect William McDonough - a consulting professor at the university.
Speaking shortly after her lecture, Diaz had nothing but praise for McDonough, who was once dubbed 'Hero for the Planet' by Timemagazine.
She said: 'He's very charismatic [and] charming. Bill is one of those people who is thinking big, but also producing.'
Diaz's surprise lecture will be shown later in the year on mtvU.