Gov. Rick Perry, who has said he hopes to make abortion “a thing of the past,” signed the legislation in July. It had been temporarily derailed when Wendy Davis, a Democratic state senator, mounted an 11-hour filibuster in the Republican-controlled Legislature. Ms. Davis is now running for governor, with abortion rights as one of her planks.

Texas officials quickly said they would appeal the decision to the Court of Appeals for the Fifth Circuit, in New Orleans, and Judge Yeakel said that “at the end of the day, these issues are going to be decided definitively not by this court, but by either the Circuit or the Supreme Court of the United States.”

Courts in Alabama, Mississippi, North Dakota and Wisconsin have blocked similar admitting-privilege requirements as part of the continuing battles over how much states may restrict the right to abortion granted by Roe v. Wade in 1973.

Monday’s ruling was hailed by the chief executive of Whole Woman’s Health, a private group that had warned that it could be forced to close its clinics in McAllen, Fort Worth and San Antonio because those clinics use visiting doctors who cannot obtain admitting privileges locally. “We are very relieved,” said the chief, Amy Hagstrom Miller.

In bringing the suit against two parts of the sweeping anti-abortion law adopted in July, abortion rights groups said that the provisions would have “dramatic and draconian” effects on women’s access to the procedure. But lawyers for the state argued that these predictions were exaggerated and that the measures served the state’s interest in “protecting fetal life.”