The previous high was seen in the week up to March 20, when 8,631 patients were waiting longer than four hours – the Scottish Government’s target time for patients to be assessed and discharged or admitted.
During the same week, 2,647 people waited more than eight hours while 1,043 people waited more than 12 hours.
The latest figures show that in the week up to June 26 one third of people waited more than four hours.
Just 67.5% of the 27,646 attendances were seen in the time frame, short of the 95% government target.
That figure decreased slightly from 68.1% the previous week.
Similar figures for the month of May showed more than a quarter (73%) of people waiting longer than the target time.
Some 9,953 people (7.4%) waited longer than eight hours while 3,284 patients (2.5%) were in emergency departments longer than 12 hours.