The effect of short-term exposure to copper on the cellular and physiological response in haemocytes of juvenile abalone Haliotis rufescens cultivated in hatcheries in the north of Chile is evaluated. The animals were exposed for 168 hours to concentrations of 2.5 μg/L and 10 μg/L of Cu+ 2, which have been reported as representative of coastal zones close to mining activity, particularly copper mining. The haemocytes were collected from the animals and the effect of the metal was quantified through the total haemocyte count (THC), phagocytosis, phenoloxidase activity, and generation of superoxide anions. The results showed that copper exposure decreased THC and phagocytosis significantly, while phenoloxidase activity and superoxide anions production increased significantly with respect to untreated controls. This study suggests a relation between exposure to the trace copper concentrations and the alterations of in vitro cellular and physiological parameters of the abalone's immune system in a dose- and time-dependent manner. This study emphasize the importance of heavy metal contamination on abalone cultures considering that the haemocytes are crucial for the proper function of the immune system and important health indicators to evaluate the effect of ambient stress factors on these organisms.