We present here the case of a fetus with constriction band syndrome involving the skull and brain. Whereas prenatal ultrasound did not show direct signs of this condition, fetal magnetic resonance imaging (MRI) revealed it clearly. This may be the first case of constriction band syndrome to be diagnosed using fetal MRI. As a supplementary tool, fetal MRI may lead to an accurate diagnosis when prenatal ultrasound presents equivocal findings with respect to central nervous system development.