Chief executives and finance directors in struggling trusts were of insufficient calibre, and boards lacked cohesion due to a high turnover of staff, says the report, published last week.
The trusts had often failed to engage senior clinicians in core management processes, an oversight the report identifies as 'a reliable indicator of impending financial trouble'.
The findings were reached after a review of 25 public interest reports on failing trusts, including 14 PCTs, issued by the watchdog in 2005/6.
'Received wisdom is that boards have concentrated on access targets and standards of patient care at the expense of financial discipline or that quality lapses are caused by limited funding. Neither is correct,' the report stated.
NHS Alliance chairman Dr Michael Dixon said: 'Clinicians determine how much the NHS spends. If they are not involved in PCT strategy, how can they make ends meet?'