Asphodelus aestivus (A. aestivus) is a common plant in the meadows in Aydin region, Turkey. Severe neurologic syndromes accompanied by intense neurovisceral lipofuscinosis were observed in sheep exposed to A. aestivus leaves and seeds in the same region. Findings from dead sheep indicated that consumption of A. aestivus seeds resulted in neuronal lipofuscinosis. Hence, an experiment with four treatment groups was carried out to induce neuronal lipofuscinosis in sheep consuming A. aestivus seeds at different levels in the diets. Animals in treatment groups were fed with total 600 g/daily yearling feed including 0% (Control group; animal 1 and 2, 2 years old - animal 3; 3 years old), 5% (Treatment I; animal 1 and 2; 2 years old), 10% (Treatment II; animal 3; 3 years old - animal 4; 2 years old) and 15% (Treatment III; animal 5 and 6; 2 years old) of A. aestivus seeds during the first four months of the experiment. Then they were fed with total 600 g/daily yearling feed including 0% (Control group), 15% (Treatment I), 20% (Treatment II) and 35% (Treatment III) of A. aestivus seeds during the last two months of the experiment. At the end of the experiment, systemic necropsies of the sheep were performed. Tissue samples were collected from all organs and fixed in 10% neutral formalin. After the samples were stained with hematoxylin eosin, they were examined by light microscope. The ultrastructural sections prepared from pons and medulla oblongata were examined by electron microscope. Clinically, a general toxicity accompanied by loss of weight, transient paresis and hyperesthesia was observed in the Treatment III. The neuronal lipofuscinosis were determined particularly in neurons of the brain stem and in myenteric plexus of the intestines of sheep on the test diets.