We report a diabetic patient who developed skin lesions on her left forearm and ulnar nerve involvement following admission to the hospital and putting IV catheter for her treatment. Biopsy samples wee taken from her skin lesions and ulnar nerve and with further evaluation after 2 months, the diagnosis of fungal infection due to zygomycetes and mucur was considered based on the presence of non-septal hyphas with spreading to adjacent blood vessels. In specific staining, the sample was positive for fungal elements but its culture was negative. Clinical healing was observed after treatment with IV Amphotericin B. In general, in every diabetic or immunosupressed patient, even normal individuals with unusual infections without any response to common antibiotics, the possibility zygomycosis should be considered and histopathologic and fungologic evaluation should be done.