Three groups of rats were infected with Trypanosoma brucei. Two of the groups were treated with either asteroidal (Cortisol) or a non-steroidal (Voltaren) anti-inflammatory drug to compare the effects of the two drugs on the disease process. The anaemia was least severe in the Cortisol treated group which suggests that its supportive use in the treatment of natural infections with the brucei subgroup of trypanosomes may be advantageous.