OBJECTIVE: To estimate the association between professional liability insurance premiums for obstetricians and late preterm induction (LPI) rates. DESIGN: Data from the National Center for Health Statistics were used to identify all Illinois women pregnant with singletons at 34 weeks' gestation from 1991 to 2003. The independent association between LPI (induction between 34 and 37 weeks' gestation) rates and the previous year's obstetric malpractice insurance premiums was evaluated using linear regression. RESULTS: The mean annual LPI rate (5.4/1000 in 1991 to 15.2/1000 in 2003, P < 0.001) nearly tripled, and obstetricians' professional liability insurance premiums ($55,480 to $110,613, P < 0.001) approximately doubled. After adjusting for race, previous cesarean delivery, marital status, and the presence of antepartum risk factors for indicated preterm delivery, LPI rates increased by 1/1000 births (P = 0.004) for each annual $10,000 increase in the county's obstetric malpractice insurance premium. CONCLUSIONS: Rising premiums are associated with increased frequency of LPI among women with singleton gestations.