BACKGROUND:Paraneoplastic peripheral neuropathies may develop any time during the course of the neoplastic disease. These neuropathies are often masked by concurrent neurotoxicity from chemotherapy and other cancer therapies. MATERIALS AND METHODS: Here, we report a case of a 40 year old female who was diagnosed as Guillain Barre Syndrome in a known case of triple negative breast cancer on second line chemotherapy. Patient presented with gait disturbances and slurred speech 2weeks after receiving a 3rd cycle of second line nanosomal Docetaxel based chemotherapy. This case had a diagnostic dilemma.First we suspected brain metastasis, but MRI brain was normal. Nerve conduction study results led to suspicion of Docetaxel induced neurotoxicity.Csf cytology report showed raised protein levels and negative for malignant cells. Finally a diagnosis of paraneoplastic neuropathy or Acute Inflammatory Demyelinating Polyneuropathy (Guillain Barre syndrome i.e. GBS) was made.Patient was treated with intravenous immunoglobulin and other supportive measures.But Patient’s condition deteriorated, and expired in ICU course. CONCLUSION:GBS in cancer patients should be differentiated from chemotherapy induced toxicity & neuropathy, particularly as effective treatment is available for GBS like Paraneoplastic syndrome