The bill would have required women to wait 72 hours before deciding to have an abortion.
In a statement, Governor Nixon said he vetoed the bill because it contained no exceptions for victims of rape or incest.
"This glaring omission is wholly insensitive to women who find themselves in horrific circumstances and demonstrates a callous disregard for their well-being," said Nixon. "It victimizes these women by prolonging their grief and their nightmare."
Utah and South Dakota are the only two other states to require a 72 hour waiting period for abortions.