By Helena Oh

Yale School of Management and Stanford Graduate School of Business couldn't do it. Harvard Business School didn't even come close. The Tuck School of Business at Dartmouth College is the only business school in the country to have more than 50% of its alumni contributing to the alma mater's annual funds, 64%, in fact. Performance of other schools simply pales in comparison. Overall, Texas Tech University (not ranked) is runner-up with 48%, but the majority of schools fall under 20%. A few notable exceptions are: Yale University (47%), Stanford University (41%), and University of Virginia, Darden (40%).

Just how does Tuck do it? To some extent, the high alumni participation rate is a function of Tuck's size. Its graduate network of 7,738 alumni is the smallest of BusinessWeek's top 10 B-schools, making it easier to convince a larger portion to cough up. And it's the school's small size that's giving it a competitive advantage.

IT'S A GIFT.  But the University of Virginia's Darden Graduate School of Business Administration also has a small collegial community, and its annual alumni giving rate is 24 percentage points lower than Tuck's. Its class size grew 25% from 2004, yet Darden still has fewer living MBA alumni. "We're happy to sustain the 40% while increasing the class size by 25%, [but] we certainly look to Tuck as a model for us," says Ann Taylor, executive director of the Darden School foundation.

At most schools, including Tuck, the annual fund pays for anything not covered by the school's endowment, including faculty salaries, snow plowing, scholarships, even the heating bill. At most top B-schools, about 60% of the annual fund comes from alumni donations, with the balance coming from wealthy non-alumni donors. But at Tuck, virtually the entire annual fund -- 87% -- is the result of alumni giving, a fact that leaves less margin for error. "At a school like Tuck, I'd say it depends on gifts more than most schools," says Tuck Dean Paul Danos.

As frightening as that sounds, it may work to Tuck's advantage. Schools with large and growing endowments that provide more than adequate cash for their needs sometimes pay the price when alumni redirect their contributions elsewhere, arguing that their small contributions simply aren't needed. At Tuck, smaller donations are the norm, so donors know their contributions count.

HOOK 'EM EARLY.  Tuck has one of the smallest average alumni gifts of the seven top-10 B-schools that reported that information to BusinessWeek -- $836 compared to $1,583 for Stanford, $5,102 for Columbia Business School, and $7,644 for Harvard. But they add up. The annual fund is $4.35 million in total and of that, about $4.26 million comes from alumni.

One way Tuck beats the big boys at the fund-raising game is by instilling the habit of giving at an early age. Unlike some rival B-schools, Tuck doesn't have the luxury of letting recent alumni off the hook. In the early 1980s, the school started a class giving program, with members of each departing class making a contribution before they even leave campus. Tuck is not alone among B-schools in tapping its outgoing students for cash, but it has been unusually successful. Since the program began, participation rates have shot up from 70% to more than 90%.

Yale and the Stephen M. Ross School of Business at the University of Michigan are seeing similar results, but only time will tell whether it will translate into the long-term annual alumni giving that Tuck is witnessing. At Michigan, $1.51 million of the $2.64 million in the annual fund comes from alumni. At Yale, it's $773,434 of the total $2.73 million.

TEAM SPIRIT.  "[Tuck has] the best peer-to-peer fundraising program in the country, and I think that kind of approach works in small schools," said Nevin Kessler, Yale School of Management's associate dean for development and alumni relations. Tuck's small-town location in Hanover, N.H., creates a team spirit that lasts long after students leave.

For big schools with rich endowments, getting two out of three graduates to contribute may not be possible. But for Tuck -- a small school with a devoted following -- it seems to work.

Editor's Note: This article has been revised since original publication on BusinessWeek Online. An earlier version contained an incorrect figure for alumni giving at Bowling Green State University.