Isosulfan blue dye can be used to mark the sentinel lymph node during various surgeries. The dye was known to have minimal side effects, but recently a few cases of an anaphylactic reaction were reported in melanoma and breast surgery. We experienced an anaphylactic reaction during peritumoral injection of this dye in a patient with cervical cancer. Immediately after dye injection, the patient showed an anaphylactic reaction with cardiovascular collapse and oxygen desaturation. We resuscitated the patient and she recovered without complications.