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This research is about the effect of Cd2+ on the growth and morphology of saffron (Crocus sativus L.) roots with use of light microscopy. Saffron bulbs were rooted in glass distilled water in the presence of various concentrations (up to 50 mg/l) of Cd2+ for 3 days. Roots were counted and measured each day and their morphology was examined under a light microscope. After the first day, root counting showed a substantial decrease in the number of roots per bulb in up to 2 mg/l Cd2+, dropping to 20% - 60% of the control. However the number of roots per bulb became closer to the control values after the second and third day of incubation in Cd2+. For Cd2+ concentrations over 2mg/l, the number of roots per bulbs counted after the first day was also reduced to 37% of the control and after the second and third day, the number of roots became closer to the control values. A critical Cd2+ concentration of 5mg/L was determined above which root growth was completely inhibited after the first day. Below that concentration, root growth was merely slowed down. Light microscopy observations indicated that: cells from the epidermal and subepidermal regions, and cells from the central cylinder showed marked morphological alterations starting at 5 mg/l Cd2+. For the cap and meristem region cells, morphological changes were observed already in 2 mg/l Cd2+. These results were confirmed by comparing ratio of the nuclear surface area over the cytoplasmic surface area. Thus it appeared that the cap region and the meristem region were the most sensitive area to the toxic effect of cadmium. However cell death was observed in cap cells first.