The case was thrown out after a judge said that the plaintiffs had waited too long to sue the defendants, who between them controlled 70 percent of the market.
Now the 9th US Circuit Court of Appeals in San Francisco said Judge Jeffrey White in San Francisco made a mistake when he threw out the case.
Circuit Judge Richard Paez said the alleged violations were "continuing" each time the defendants sold new SD cards, and because it would have been "speculative" that there was any harm before those sales were made.
"Plaintiffs should not be penalised for failing to foresee earlier that they would enter the market for SD cards and would therefore be harmed by defendants' conduct," Paez wrote for a three-judge 9th Circuit panel.
The alleged violations stemmed from a 2006 licensing agreement that let Panasonic, Samsung and Toshiba set a "fair market price" for SD cards, and imposed royalties on cards sold by other manufacturers.
But the lawsuit was not filed in March 2011, but was brought on behalf of purchasers of SD cards in the prior four years. It sought a halt to the alleged price-fixing, as well as damages.
Now the case will be returned to Judge White and can go ahead.