Acute and early life stage toxicity tests were conducted with trivalent chromium and steelhead trout (Salmo gairdneri). A 96-h LC50 of 4,400 micrograms/l chromium was obtained with two-month-old juvenile fish. Early life stage exposure from newly fertilized eggs to 30-d post-swimup produced complete mortality at 495 micrograms/l, and significantly reduced survival to hatch and to the end of the test at 157 and 89 micrograms/l, respectively. An early life stage test started with eyed eggs produced similar results, with hatching survival significantly reduced at 271 micrograms/l. An acute test conducted with fish surviving the early life stage test showed that no acclimation resulted from previous chromium exposure.