However, his etchings stunned fellow diners, who thought he belonged to a notorious gang.
Viggo told the New York Daily News newspaper: "I went into a Russian restaurant in London. People saw the tattoos and stopped talking. They must have thought I was a real mafia man. It happened a couple of times. After a while, I figured I better wash off the ink before I went out to eat."
Although those tattoos were fake, Mortensen does have a real piece of body art.
The 'Lord of the Rings' star has an 'H' on his wrist as a tribute to his son Henry.
Mortensen - who is now divorced from Henry's mother Exene Cervenka - said:
"When he was little and he first started to write, he wanted to write Hs everywhere, all over my arms. It was either that or the wall, so I said, 'Go ahead.'
"One day he put one right there and it was beautiful and I thought it would be a nice memory to have. I went right down to a tattoo parlour on Sunset Boulevard in Los Angeles and had a guy tattoo over it."