Adrenal insufficiency or Addison's disease is actually a rare illness associated with numerous pathologies. We describe the case of a fifty years old male with lung adenocarcinoma and metastasis in both adrenal glands, who was receiving chemotherapy with mytomicin, ifosfamide and cisplatin (MIC), and was diagnosed of adrenal insufficiency as a result of acute episode addisonian crisis. Many times, the clinic symptoms of adrenal insufficiency can go unnoticed due to its low specifity and to mixing up with other syndromes. Hypoadrenalism has been described in association with many tumours, specially with non-Hodgkin's lymphoma. It seems that there is a discordance between the number of patients with bilateral metastatic adrenal destruction and the documented cases of clinic insufficiency. Once the adrenal failure is suspected, the diagnosis and hormone replacement treatment are really easy. Addison's disease ethiologies are revised putting special emphasis on those related with cancer patients.