Family
Robert's son Ty Trujillo also plays bass guitar in the youth rock band The Helmets. In April 2017, at the age of twelve, Ty Trujillo joined nu-metal band Korn, replacing their main bassist on a South American concert tour. 

Stage image
Rob often moves around the stage with a peculiar "crab" gait with his guitar held low, makes creepy grimaces, jokes, and mimics something with smooth hand movements. Almost always performs in shorts-bermudas. At the beginning of Metallica's career Rob did not sing much, but eventually became the main backing vocalist of the band.