We report six case histories of malignant tumours following abortion of moles. In three cases their surgical removal allowed us to control them by histology: two of these were destruens chorio-adenomata, one case only was a choriocarcinoma. In the three other cases the cure was obtained by the sole use of anti-mitotic drugs. This treatment was undertaken on bioclinical evidence of malignancy which is certainly not foolproof, but which is practical in use, when one appreciates how difficult it is to diagnose some of these post-mole tumours histologically. There is a place for the surgical treatment of these cases in spite of the usefulness of Methotrexate. This place varies according to the age of the patients and the resistance of the tumours to treatment with anti-mitotic drugs.