Hyaline eosinophilic globules have so far been described in a restricted variety of tumour types. We have noted their presence in a variety of gynaecological malignancies, in particular mixed Müllerian tumours and other epithelial ovarian tumours. We therefore studied their incidence and distribution in a series of malignant, borderline and benign epithelial ovarian tumours, and endometrial and endocervical adenocarcinomas. Hyaline eosinophilic globules were found in all 30 mixed Müllerian tumours from various sites in the female genital tract, 22 of 30 clear cell carcinomas, seven of 30 serous, two of 30 mucinous, and one of 30 endometrioid carcinomas examined, and were also seen in metastases from these tumours. They were present in only two of 25 borderline serous, one of 25 borderline mucinous tumours, and in four of 50 benign serous and one of 50 benign mucinous tumours. The globules were not found in any of 25 Brenner tumours examined, nor in 30 endometrial or 30 endocervical adenocarcinomas. The globules were periodic acid-Schiff positive after diastase, stained positively with PTAH, and were immunoreactive for alpha-1-antitrypsin. This study therefore demonstrates that eosinophilic globules are not specific for any particular tumour. However, their frequency in malignant mixed Müllerian tumours suggests that this diagnosis should be carefully excluded whenever these globules are present in epithelial tumours of the female genital tract.