The Judicial Conduct Commissioner says he is troubled by the number of complaints he is receiving about judges, which he does not have enough staff or resources to deal with.
Sir David Gascoigne's office handled 319 complaints in the year to August, a rise of more than 200% since the office opened in 2005.
High Court judges were complained about most often.
Sir David says complaints are becoming increasingly complex and are taking longer to deal with, while others accumulate behind them.
He says he does not have enough staff, premises or equipment and the situation is limiting the effectiveness of the office.
Sir David says he is hopeful that discussions underway with the Justice Ministry might resolve the problem.
This is the second consecutive year Sir David has highlighted the problem in his annual report.