Preterm birth is defined as delivery of the baby after the period of viability and before 37 weeks of pregnancy. Preterm birth complicates 10–15% of all pregnancies and is a leading cause of neonatal morbidity and mortality. Idiopathic preterm labor accounts for about 40% of all preterm births. Assessment of risk of preterm delivery should be done at each antenatal visit concentrating on identification of modifiable risk factors. Clinical criteria of diagnosis include: (i) Four contractions in 20 minutes or eight in 60 minutes and progressive change in cervix. (ii) Cervical dilatation greater than 1 cm. (iii) Cervical effacement of 80% or greater. Diagnostic goals are to identify etiology and to differentiate true from false preterm labor. Cervical length estimation by ultrasound along with fetal fibronectin testing have been used to differentiate true from false preterm labor. A negative fibronectin and a long cervix > 1.5 cm are strong negative predictors of imminent preterm birth. Therapeutic goal is to identify the subgroup of women who will benefit from tocolysis and corticosteroids. Pregnancies between 24 to 34 weeks of gestation or estimated fetal weight between 600 to 2500 gm with no evidence of infection, benefit from tocolysis. Once a pregnancy has continued beyond 34 weeks, fetal survival rate is within 1% of the term survival and long-term sequelae are rare. Hence steroids and tocolysis may not provide additional benefit. Acute tocolysis should be used to allow enough time for the effect of steroids after ruling out contraindications. There is limited role of bed rest, hydration and sedation in these women.