Asbestos is known to cause lung diseases in occupationally exposed workers. These properties have restricted its use. Industries have been exploring the possibility of other mineral fibres to replace the asbestos. In this direction, wollastonite has gained great attention owing to its high thermal resistance. In the present paper, the toxicity of three samples of Indian wollastonite was compared to that of chrysotile. Dust suspensions were added to the red blood cell suspensions to obtain a final dust concentration of 1.0-5.0 mg ml-1 in the system. The wollastonite varieties were found to have smaller haemolytic potential in human red blood cells than that of chrysotile in vitro. Chrysotile also was more effective in inducting peroxidative damage of polyunsaturated fatty acid (PUFA) than wollastonites in the present system. The peroxidative damage of PUFA and the haemolysis were both time and dose dependent. A higher value of malonaldehyde (a lipid peroxidation product) formation in low-speed supernatant of haemolysate was observed than in the intact cells. As the free-radical scavengers vitamin E and reduced glutathione prevent haemolysis and lipid peroxidation, these data are consistent with the involvement of lipid peroxidation in the haemolytic process.