In 30 patients with Lyme disease, the lesions of erythema chronicum migrans were absent or atypical. Thirty biopsy specimens were obtained from cutaneous lesions of these patients. The predominant histological finding was a superficial dermal and deep perivascular and interstitial infiltrate composed mostly of lymphocytes but containing a few eosinophils and plasma cells. In serial sections with a silver stain, a few Borrelia burgdorferi were found in the biopsy specimens from cutaneous lesions in five patients. Thus, there is evidence that the typical lesions of erythema chronicum migrans of the classical Lyme disease do not develop while Borrelia burgdorferi survive and persist in cutaneous lesions.