The aim of the study was to assess the activities of the collagenases type IV (matrix metalloproteinase type 2 [MMP-2] and matrix metalloproteinase type 9 [MMP-9]), also known as gelatinases, and the local activity of interstitial collagenase (matrix metalloproteinase type I[MMP-1]) in tissue extracts from a case of the botryoid sarcoma, a rare and very malignant tumour of the female genital tract. Zymography revealed that botryoid sarcoma does not express the 92-kDa form of type IV collagenase activity in Triton extract and only weak activity in Heat extract when compared to values found in extracts from striated muscle and fibroma uteri. MMP-1 appeared in the latent form only in the Triton extract of botryoid sarcoma and its activity was lower than those found in the control tissues. These results indicate that the very rapid local invasion and systemic metastases associated with botryoid sarcoma do not depend on the activity of tumour-derived gelatinases.