All possible hybrid crosses between brook (Salvelinus fontinalis), brown (Salmo trutta), and rainbow (Salmo gairdneri) trout were made and a portion of the fertilized eggs from each mating were heat shocked to induce triploidy. Within a species, triploids generally showed poorer survival to the initiation of feeding than diploids. In most crosses, however, triploid hybrids showed much better survival than diploid hybrids. The triploid tiger trout (brown × brook) hybrid showed the most potential of the hybrids tested. Induced triploidy could be a useful general method for increasing survival in interspecific fish hybrids.