The product-liability lawsuit, filed on behalf of Chad and Melissa Hodgson, contends that the Golden Corral Restaurant in Kearney prepared and served contaminated lettuce.
State health officials have said at least 73 people who ate at the restaurant during the last weekend in February, or who came in contact with someone who did, became ill with E. coli O157:H7 bacteria.
The source of the outbreak is believed to be contaminated head lettuce, but health officials have not confirmed it.
The lawsuit was filed by attorneys William Marler of Seattle and Nancy Freburg of Kearney. No amount of damages was specified.
Marler is with the Marler Clark law firm, which has been involved in other E. coli litigation.
The Hodgsons ate at the restaurant Feb. 26, according to a press release from the law firm. Melissa ate a large lettuce salad.
On March 1, she began to feel ill, and three days later she started to have severe and frequent bloody diarrhea. Tests indicated she had the E. coli bacteria, the law firm said, but she was not hospitalized and began to feel better March 8. Chad did not become ill.
"But there are still medical concerns about the long-term impact of the bacteria on her body," the firm said.
Restaurant officials were not immediately available for comment.