1.1. Freshwater cichlids Oreochromis mossambicus (tilapia) were exposed to 10 μg Cd/l in ambient water for 2,4, 14 and 35 days. Plasma cortisol and glucose levels were determined to evaluate if cadmium induced a typical stress response in these fish.2.2. Exposure to cadmium for 2, 4 and 14 days elicited a significant elevation of plasma cortisol levels.3.3. A significant hyperglycemia occurred on days 2 and 4 in cadmium-exposed fish.4.4. During long-term exposure to cadmium (35 days), the plasma cortisol and glucose levels returned to control values. This recovery after 35 days indicates the ability of tilapia to adapt to low cadmium concentrations in the ambient water.