Six cases of cervical large cell neuroendocrine carcinomas (LCNEC) were found among 972 patients (0.6%) with invasive cervical carcinoma. The patients, who were from 27 to 51 (mean 38) years of age, presented with vaginal bleeding or an abnormal Papanicolaou smear. Five tumors were stage Ib and one was IIa. All patients underwent radical hysterectomy and received adjuvant chemotherapy and pelvic radiotherapy. Four patients died of tumor 6 to 19 months (mean 14 months) postoperatively. On histologic examination, the tumor cells were arranged in an organoid growth pattern and were larger than those of typical small cell carcinoma. Glandular differentiation was present in one case. Mitotic figures ranged from 15 to 45 (mean 29) per 10 high-power fields. Prominent vascular invasion and necrosis was seen in all of the tumors. Each tumor was immunoreactive for chromogranin A and/or synaptophysin. The results of this study confirm the aggressive nature of cervical LCNECs. The recognition of LCNECs is necessary to establish the most effective treatment for these aggressive tumors.