When Kevin Hua, 18, got rejected by the University of California, Davis, a school he coveted--it felt like the end of the world. "I guess I cried a couple of times," he confesses. But it wasn't the end. Hua, a graduate of Valley Christian High School in San Jose, Calif., was unwilling to give up. Knowing he faced steep odds, Hua set to work on a little-known last hope for the bounced applicant: the letter of appeal.

Though universities don't advertise it, many schools will reconsider if the rejected student can make a persuasive enough case. At the University of Wisconsin-Madison, for instance, the admissions office says an appeals letter might include additional letters of reference or explanations about changes in health or family circumstances that could have affected student performance. UC Berkeley requires "significant new information" in an appeal. The University of Michigan says letters of appeal must be buttressed with documentation from outside sources. It doesn't usually work. A Wall Street Journal sampling of colleges notes that USC accepted only 32 of 500 appeals in 2004. The University of North Carolina at Chapel Hill let in just three of 75 appeals. But that's better than none.

Fighting for his chance, Hua spent a week working on an appeals letter, writing four drafts and consulting academic advisers. He noted that his grades had soared in his senior year. Hua also explained he chose Davis partly because he wanted to stay near his autistic brother, Kevin. He said that his parents were immigrants and needed guidance in finding help for Kevin. Because of his brother's experiences, Hua said he was drawn to a Davis institute that focuses on neurodevelopmental disorders, especially autism. "I truly believe UC Davis will in the near future make breakthrough discoveries in the study of autism," he wrote. "I want to be a part of this organization." For the next eight weeks, Hua waited and hoped. Then came the word: he'd been accepted. It was a lot of work, he says. But he recommends the appeals process to determined students "if you really want to go."