1 (20 oz.) can crushed pineapple with juice
1/2 c. chopped walnuts
1/2 c. mini marshmallows
1 box instant pistachio pudding
1 (9 oz.) container Cool Whip

In bowl, blend pineapple and juice with nuts and dry pudding mix. Mix and add marshmallows and fold in Cool Whip. Refrigerate.