Lentinula edodes shiitake mushrooms are rich sources of iron, which in addition to their relatively high nutritive value are also characterized by high contents of biologically active components. However, recommendation of products prepared on the basis of dried shiitake mushrooms and introduced to the diet as sources of iron requires a precise determination of bioavailability of this element. The purpose of this study was to assess the bioavailability of iron from cereal products with the addition of dried shiitake mushrooms using the iron regeneration efficacy method in Fe-deficient female rats. Feeding products with 10% and 20% addition of dried shiitake to female rats with a previously evoked Fe deficiency resulted in a gradual repletion of lowered Fe indices, including an increase in blood hemoglobin concentration and serum and liver Fe levels to values comparable to those of the control group. Bioavailability of iron from cereal products enriched with dried shiitake mushrooms is comparable to that of Fe(II) gluconate.