The present study was undertaken to investigate the consequences of copper (Cu) and lead (Pb) stress on biochemical properties and mitotic chromosomal behavior of Thelypteris interrupta (Wild.) K. lwats and Thelypteris dentata (Forssk.) E. P. St. John. and their efficiency to accumulate and tolerate those metals. The plants were planted in pots containing different concentrations (0, 50, 100, 500 and 1000 mg kg−1) of Cu and Pb salts in the soil and were incubated for 20 weeks. Cu and Pb accumulation by both the ferns was found to be increased with increasing metal concentrations. In case of T. interrupta, maximum accumulation of Cu and Pb in the above ground part found were 68.73 mg kg−1 DW and 35.87 mg kg−1 DW respectively while in the underground part they were 127 mg kg−1 DW and 215.4 mg kg−1 DW. On the other hand, T. dentata had maximum Cu and Pb accumulation in the above ground part were 35.5 mg kg−1 DW 44.87 mg kg−1 DW, and in the underground part, they were recorded as 117.2 and 184 mg kg−1 DW respectively. A gradual increase in antioxidative enzymes (peroxidase, superoxide dismutase and catalase) with increasing metal dose was observed. However, no significant change was found in case of catalase activity in T. interrupta. Both metals exerted a negative effect on the mitotic index of both studied ferns and resulted in different types of mitotic chromosomal abnormalities. Nonetheless, antioxidative defense system of plants got activated due to heavy metal stress condition that eventually conferred protection against oxidative stress. Both the studied ferns seemed to be good accumulators and tolerant to Cu and Pb.