Neuroendocrine carcinomas of the cervix are very rare, accounting for only 1–2% of all cervical cancers and <1% of all neuroendocrine tumors. Small-cell carcinoma of the cervix is associated with poor prognosis, even in early stages. Despite their neuroendocrine origin, tumors presenting with syndromes due to secreted neuroendocrine hormones are extremely rare. To date, only seven cases of cervical small-cell carcinoma associated with Cushing’s syndrome due to ectopic ACTH secretion have been described. In most reports, Cushing’s syndrome associated with these tumors occurred only in association with liver or lung metastasis. Only one single case of primary uterine cervix carcinoma secreting enough ACTH to induce Cushing’s syndrome in the absence of metastatic disease has been described in 1994. Here, we describe a case of cervical small-cell carcinoma presenting with an acute onset of severe hypokalemia in Cushing’s syndrome without metastatic disease to distant organs.