Tomato seedlings (Lycopersicon esculentum), initially cultivated in a basic nutrient solution during 12 days, were treated with increasing CdCl(2) concentrations for 10 days. The results showed that cadmium inhibited the weight growth depending on the metal concentration and the plant organ. In the presence of 20 microM CdCl(2), the addition of calcium, 0.1 to 10 mM of CaCl(2) in the culture medium, improved especially the biomass production and the mineral composition of the plants in concomitance with an increase in the contents of photosynthetic pigments. Histological study at the hypocotyle level revealed that cadmium (20 microM) induced a restriction of the tissue territories as well as meristem formations differentiating in a root structure. At this concentration, the addition of CaCl(2) (5 microM) was characterized by an opposite effect with absence of meristem structures. The overall results suggest that the alteration of some plant growth process after exposure to cadmium can be attenuated by an adequate calcium contribution in culture medium.