The actor took to Instagram to reminisce about the film and posted a picture of himself and a group picture of the cast of the film from the premiere.
Decked up in a black suit, Ruffalo is seen posing at the purple carpet event in the picture.
"Feeling nostalgic that it's been a year since #AvengersEndgame was in theaters. Thank you all for being a part of this wild journey with us #LoveYou3000," he captioned the picture.
The film 'Avengers Endgame' by Marvel comics was released on April 26 last year and became a blockbuster hit within few days of hitting the screens.
( With inputs from ANI )