Here we report two cases of annular erythema caused by Ixodes persulcatus tick bites without positive results for Lyme borreliosis infection. Case 1, a 60-year-old female, hiked around Mt. Eboshidake in Nagano prefecture on July 14 and found a thumb-sized erythema with a tick on her waist on July 20. The biting tick was spontaneously removed. An annular erythema of 55×36 mm in size was recognized on July 25. She had no systemic symptoms or abnormal laboratory data. Histopathological study showed dermal inflammatory infiltrates and the degeneration of collagen fibers, which suggested a tick bite. Case 2, a 38-year-old female, hiked around Mt. Daisetsuzan in Hokkaido prefecture between July 15 and 18. She found a biting tick on her back and removed it on July 22. An annular erythema developed and expanded between July 25 and 29. Skin rashes in these cases were successfully treated with oral amoxicillin or minocycline and had almost disappeared 2 weeks later. Sera antibody titers against Borrelia afzelii, B. burgdorferi, and B. garinii were negative. These cases indicate that annular erythema associated with tick bites is not always Lyme disease, but can be due to a tick-associated rash illness.