Placentomegaly is an important ultrasound finding in pregnancy. It may be asymptomatic or sometimes cause life threatening complications than a normal sized placenta and could also serve as a clue for poor feto-maternal outcome. We report a 29-year-old G2P1+0 (1 Alive) now P2+0 (2 Alive) with one previous caesarean section and an ultrasound diagnosis of placentomegaly at a gestational age of 35weeks+4days who had a repeat caesarean section at a gestational age of 35weeks+ 5days on account of reduced fetal movements. She was delivered of a live male 2.6 kg neonate with APGAR score of 8 at one minute and 9 at 5 minutes of life and placenta weight of 1.6 kg. Mother had primary postpartum haemorrhage (PPH) secondary to uterine atony. She subsequently had a caesarean hysterectomy due to protracted bleeding and failure of all other interventions to stop the bleeding with a high index of suspicion of a gestational trophoblastic disease especially an invasive mole as the cause of the bleeding. The uterine and placenta tissue were sent for histology which confirmed invasive(destructive) mole (chorioadenoma destruens). Maternal and perinatal mortalities were prevented following prompt intervention and a high index of suspicion.