In his keynote conference speech, GPC Scotland chairman Dr Dean Marshall questioned whether the initiative had been a good use of limited NHS resources.
'In these difficult financial times, is it really appropriate for us to be wasting resources on what is effectively a PR exercise?' he asked.
'That is why I am calling on the Scottish government to commit to a review and evaluation of extended hours services in Scotland,' he said.
Dr Marshall said anecdotal evidence suggested that appointments at urban practices were taken up by patients who could have attended in the day.
This included the elderly, the unemployed and the long-term sick, while appointments in rural areas remained unfilled.
'GPs sit in empty buildings waiting for a demand that does not exist,' said Dr Marshall.
He said that GPs at the conference last year had been angry about government policy to impose extended hours.
'For whatever reason, the government appears to be wedded to this policy,' said Dr Marshall.
He said that, while GPC Scotland had been unable to prevent implementation, it had helped to make it more acceptable.
'Local flexibility was introduced to make the system safer and more practical,' he said.
About half of Scottish practices offer extended hours.
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