Howard K. Stern said Thursday he would ask the full appeals court to rehear the case and would appeal to the U.S. Supreme Court if necessary.
Smith, who first gained fame as Playboy's 1993 Playmate of the Year, was 26 when she and oilman J. Howard Marshall II married in 1994. He was 89. They had met three years earlier when she was working as a stripper.
Marshall died in 1995, and Smith and Marshall's son, E. Pierce Marshall, have battled over his estate ever since.
A three-judge panel of the 9th U.S. Circuit Court of Appeals ruled that a Texas probate court's decision that the son was the oilman's sole heir should stand. The panel said the federal judge in California who ruled in Smith's favor in 2002 should never have even heard the case.
"After nine years of litigation, I'm very pleased by the judgment issued by the 9th Circuit upholding my father's wishes regarding disposition of his assets," E. Pierce Marshall said in a statement.
But Stern said the court, "on a legal technicality, reversed the judgments of two federal courts that found massive fraud and other wrongdoing by E. Pierce Marshall by which he deprived (Smith) of the property that her husband intended her to have."
Smith has not received any of her late husband's estate. The $88.5 million was put on hold during the appeals process. She has recently been seen on E! Entertainment Television's "The Anna Nicole Smith Show."
A federal court ruled in 2002 that Smith was entitled to compensatory and punitive damages because the younger Marshall altered, destroyed and falsified documents to try to keep her from receiving money from his father's estate.
Thursday's ruling reverted to the findings of a Houston probate judge, who had ruled the son is the sole heir — and does not owe Smith anything.
Smith filed for bankruptcy in 1996. As part of its ruling, the 9th Circuit said the bankruptcy court should now hear testimony on other charges she made that the court had disregarded. Included among those was that the younger Marshall exercised undue influence on his father in making his will.