The use of magnetic resonance imaging (MRI) as a complementary diagnostic method was evaluated in a group of 36 complicated pregnancies during the last trimester. Most of the examinations were carried out by two specific MRI sequences, the T1-weighted gradient echo FLASH sequence (TR 120, TE 12) and the T2-weighted fast-spin echo sequence (TR 2000, TE 90). Information additional to that obtained by ultrasonic diagnosis was obtained by MRI in 16 of the 25 cases of foetal malformation and in 5 of the 11 cases with other obstetric problems. Foetal curarization was not necessary in most of the cases. A good MRI technique, for selected obstetric problems and when used in combination with detailed antepartal ultrasonic examinations, can give useful diagnostic information to an obstetrician.