Reduced amniotic fluid volume generally leads to a poor perinatal outcome, especially when it is observed in the second trimester. The recent obstetric literatures have been reporting on various applications of amnioinfusion in the diagnostic, prophylactic and therapeutic management of oligohydroamnios. We experienced two cases of amnioinfusion, which were used to diagnose or to manage the midtrimester oligohydroamnios and we report them with a brief review.