Junior doctors are still working so hard their performance can suffer, the British Medical Association said after an inquest into a patient's death.
Junior doctors' working hours are still intense, the BMA warns
Tony Wright, 58, died at Leeds General Infirmary after a doctor gave him an insulin overdose in December 2003.
An inquest heard last week how senior house officer Dr Helen Pike made the mistake after a 100-hour working week.
The BMA said there were still problems despite a reduction in the total number of hours medics worked.
A BMA spokesman conceded that since 2003 new European health and safety legislation meant junior doctors could no longer work more than 58 hours a week.
"However, most are still close to the top of this limit, and the new law has created new problems," he said.
"Shift systems have been introduced, and it is common for junior doctors to work at full intensity for up to 13 hours, which can have an effect on their performance and decision-making.
"On top of this, many hospitals have removed the rooms where junior doctors could get some rest on a long shift, which again has implications for patient safety."
The inquest in Leeds heard how Mr Wright, of Crescent Towers, Leeds, suffered a heart attack after Dr Pike injected him with five times the normal level of insulin. He died 10 days later.
The court heard how the doctor had worked more than 100 hours in seven days after swapping shifts with colleagues and doing extra hours. She had snatched sleep when she could in a hospital room.
West Yorkshire assistant deputy coroner Mary Burke was told how Dr Pike gave the injection herself, despite the misgivings of two nurses.
But Mr Wright's family told the doctor, who is now a registrar, they did not blame her.
His widow, Freda, told her she did her best and said she accepted a mistake had been made.
The coroner recorded a narrative verdict, a statement describing the circumstances of a person's death.