The 24-year-old English actress was joined by co-stars Jamie Campbell Bower, Jonathan Rhys-Meyers, and Robert Sheehan, who were all seen pushing their hand prints into fresh concrete outside the cinema.
Earlier in the day, Lily and Jamie posed together while promoting the flick, which released on the same day, at a photo call.
FYI: Lily is wearing a Zuhair Murad dress and Christian Louboutin shoes.
15+ pictures inside of Lily Collins and Jonathan Rhys-Meyers attending a premiere for The Mortal Instruments: City of Bones… More Here! »