Objective: To find out whether it is possible to manage midtrimester oligohydramnios with traditional Korean medicine in the long term, a 32-year old woman with idiopathic oligohydramnios maintained pregnancy for 13 weeks via traditional Korean medicine (TKM) and conservative therapy, and delivered a healthy child. Methods: Conducting expectant management accompanied by antibiotics. Concurrently Gami-Dangguisan (GD), a TKM herbal decoction with effect of nourishing blood and cooling heat, was repeatedly administered with the aim of replenishing amniotic fluid. GD combined with conservative therapy Patient: A case of 32-year old woman (4-0-3-0) with 6.5mm endometrial wall in thickness and past history of 3x artificial abortion. Main Outcome: She was spontaneously conceived, able to maintain pregnancy and successfully delivered a child with C section. Main measures and the result: At 24+4/7 gestational weeks, the patient with oligohydramnios symptom was admitted to hospital for observation. Under sonographic examination at 25+0/7 weeks, amniotic fluid was severely depleted and estimated fetal weight (EFW) was 545g. Bladder and both kidneys were identified to be normal, and fetal urinary system did not reveal any pathological conditions. Doppler velocimetry outcome was also within normal limits. At 25+1/7 weeks, amniotic fluid leak self-test (AL-SENSE) was shown positive, which however contrasted with negative Nitrazine test result in further examination. Thus she was diagnosed with idiopathic oligohydramnios and planned for expectant management accompanied by antibiotics. Concurrently Gami-Dangguisan (GD), a TKM herbal decoction with effect of nourishing blood and cooling heat, was repeatedly administered with the aim of replenishing amniotic fluid. GD combined with conservative therapy improved amniotic fluid volume, which is supported by AFI elevation in subsequent sonographic observations (AFI = 8cm at 26+1/7 weeks, AFI = 11.5cm at 27+0/7 weeks). However EFW continued to be below 10th percentile, suggesting the association of intrauterine growth retardation. The patient was discharged from hospital at 27+3/7 weeks and kept pregnancy to preterm. With the onset of hypertension and proteinuria, she underwent caesarean section at 37+3/7 weeks delivering a healthy child. Conclusions: It is an exceptional case and further additional evidence is necessary TKM herbal medicine may improve amniotic fluid volume via functional adjustment of whole body.