The pranks involved the actor reprising his Beach Bum role as stoner Moondog. McConaughey, in full costume, offered passerby on Thursday regular food items that he said could get them high in a matter of seconds.
McConaughey gave a woman a regular hot dog that he referred to as a "pot dog" that was covered in THC-infused ketchup.
The woman still said she felt tingly down to her toes despite only eating a regular hot dog. The actor also gave away free samples of eye drops and juice that bystanders still said affected them.
McConaughey's Beach Bum co-star Snoop Dogg briefly stopped by, saying hello from a car while in traffic.
McConaughey and Snoop Dogg were featured recently on Jimmy Kimmel Live, detailing how they became friends and got high together while filming The Beach Bum.