1 (16 oz.) can crushed pineapple
1 (11 oz.) can mandarin oranges
1 (6 oz.) can frozen pineapple juice concentrate
1 liter vodka

Combine and chill crushed pineapple with syrup, mandarin oranges, frozen pineapple juice concentrate and vodka. Just before serving, pour over block of ice in punch bowl, add 2 bottles champagne or 2 large bottles gingerale. Stir gently.