The ACT was the only Australian jurisdiction to meet all of its elective surgery targets in 2012, according to a new Council of Australian Governments' report.
But the number of emergency department patients seen within four hours still fell well short of the territory's target of 64 per cent.
Chief Minister Katy Gallagher said on Thursday the report on elective surgery was a good result for the territory.
But Opposition Leader Jeremy Hanson said the ACT had only met all of its surgery benchmarks because the targets were set lower than other jurisdictions.
The report, released on Thursday, shows the ACT met all nine targets for elective surgery set by COAG, with patients receiving treatment within clinically recommended times - in 98.5 per cent of cases for urgent patients, 57.3 per cent of semi-urgent patients, and 88.9 per cent of non-urgent patients.
The ACT reached its benchmarks for reducing the number of days overdue patients had to wait for surgery. Of the 10 per cent of overdue patients who had waited the longest for surgery in 2011, none were still waiting for treatment by last December.
But the report shows only 56.7 per cent of emergency department patients were seen within four hours, almost eight percentage points below the target of 64.
The ACT's emergency department waiting times target and performance was the lowest of any jurisdiction.
COAG eventually wants 90 per cent of all Australian emergency department patients to be seen within four hours.
While Ms Gallagher welcomed the territory's elective surgery performance, she said emergency wait times had to improve.
But Ms Gallagher, the Health Minister, said the report showed a small improvement for the ACT's emergency departments while other jurisdictions had "gone backwards".
Western Australia was the only jurisdiction to meet its national emergency access targets (NEAT).
"They've had the four-hour rule in now for more than five years I think," Ms Gallagher said.
"The adjustments they've made are bearing fruit now. We're in the… early stages of redesign of our emergency departments and our hospital to deliver the four-hour rule.
"I'm confident that we will continue to improve but those targets are going to remain a challenge."
Mr Hanson said the report showed the territory's emergency department performance was still the worst in the country.
He said the ACT also performed poorly when actual elective surgery results were compared with other jurisdictions.
He said the COAG data showed that 57.3 per cent of semi-urgent patients in the ACT received treatment on time, compared to 91 per cent in NSW and 90 per cent in South Australia.
Mr Hanson said the benchmark for semi-urgent patients of 55 per cent was lower than other jurisdictions, where targets ranged between 60 per cent and 90 per cent.
"Because our targets are set so low compared to other jurisdictions as a result of ongoing poor performance, it can be claimed that the ACT met its targets," he said.
"The fact is those targets are set up to 35 per cent lower than other jurisdictions, which can hide the true state of our performance."