Taking bone demineralization, oxidative stress and histological alterations of certain tissues in the teleost fish Aphanius fasciatus as indices of toxicity, we compared Cd and Ca contents as well as organic and mineral matter contents in the spinal column on the one hand, and MDA, MTs, PSH contents and antioxidant enzyme activity (SOD and CAT) in the liver on the other. We also studied the histological structures of the liver and gills. The results showed that Cd induced an increase in the frequency of histological pathologies. In the spinal column. There was a negative correlation between Cd and Ca levels, with decreases in inorganic matter content and ash/dry weight ratios. These changes were associated with a reduction in PSH levels and SOD and CAT activity, while MT and MDA levels in the liver were elevated. Concomitant treatment (Cd+T°) increases the frequency and severity of histological abnormalities, as well as Cd uptake in the spinal column.