The patient was a 14-year-old girl with histories of atopic dermatitis, food allergy to buckwheat, and pollinosis. In her sixth year of primary school, she developed pharyngeal discomfort after she ate nut covered chocolate. This time she ate a cookie containing macadamia nut powder and then developed pharyngeal discomfort, followed by generalized skin flush with itching, dyspnea, headache, abdominal pain, and hypotension. She was emergently transferred to our hospital and treated with intramuscular adrenaline injection as anaphylactic shock, and then recovered. Skin prick tests were positive. Macadamia nut specific IgE (ImmunoCAP^® f345) which was examined later as a research item was 15.1U_A/mL (class 3). While she had a history of pollinosis from early childhood and an episode of pharyngeal discomfort after eating of nuts, this time she raised pharyngeal discomfort followed by systemic symptoms after eating of cookies containing macadamia nut. Therefore her symptoms were considered as anaphylactic shock caused by oral allergy syndrome (OAS) due to macadamia nut. Since OAS due to macadamia nut may lead to anaphylactic shock, rapid and reliable diagnostic methods of macadamia nut allergy possible in the common hospitals are needed to be urgently established.