(FORTUNE Magazine) – Most CEOs may know how to run their companies, but when it comes to taxes, they run for help. With the notable exception of Berkshire Hathaway's Warren Buffett, who for the most part does his own taxes, the vast majority of the business leaders queried by Fortune rely on outsiders to prepare their tax returns (see table). Many seek the expertise of Big Six accounting firms. Others, such as Dwayne Andreas of Archer Daniels Midland, stay with the firm that knew them back when they were filling out the easy forms. Andreas has been with McGladrey & Pullen in Cedar Rapids, Iowa, since Roosevelt was in office. Not surprisingly, many leaders were unwilling to talk about taxes. Sometimes their silence spoke volumes. IRS Commissioner Margaret Richardson gets help but won't identify the firm. But hasn't the IRS stated that anyone should be able to fill out any of its forms without assistance? That Steven Jobs won't say is intriguing in the aftermath of Next Computer's failed experiment in candor, where everyone from the CEO on down shared salary information. Chairman Henry Bloch also declined, begging the question: Is it possible that some firm other than H&R Block does his taxes?

CHART: NOT AVAILABLE CREDIT: NO CREDIT CAPTION: WHO DOES WHOSE TAXES