The Law Society of Scotland claims the Government's plans to lower the limit from 80mg to 50mg of alcohol per 100ml of blood will not address the worst offenders who are aware they are well over the limit.
The society says that, while it supports the Justice Minister looking into new powers given to the Parliament under the Scotland Act 2012, further information is needed on how effective the proposals would be.
Bill McVicar, convener of the society's criminal law committee, said: "While we support the intent behind the proposals, the majority of convictions relating to drink driving involve people who are not only substantially over the current limit but people who arguably know they are over that limit.
"It should therefore be questioned whether any reduction in the existing drink driving limit will tackle the worst offenders."
The Government estimates that just over one in every nine deaths on Scotland's roads each year involves drink drivers.
This equates to 30 deaths each year caused by drivers who are over the limit.
However, the society points out there is no detail of how far over the limit these drivers are.
Mr McVicar added: "Transport Scotland publishes statistics on the numbers of cases where a driver has been found to be over the limit.
"However, there is currently no information on the degree to which those with a positive reading have broken the limit. Such data would be helpful in understanding the whole picture."
Road traffic lawyer Graham Walker said it seemed "pretty daft" to have differing rules in Scotland and the rest of the UK.
He added: "Whilst I am all for Scots being leaders, I am not for them being guinea pigs."
A Government consultation on lowering the limit came to an end on Thursday. The plans – which could see drivers over the limit after one glass of wine – have already received the backing of cross-party MSPs.
A Scottish Government spokeswoman said: "We estimate that lowering the limit from 80mg to 50mg would lead to a reduction in the drink-drive death toll of between 10% and 50%."
She added the Government will consider whether there is any need for additional data on accidents – including alcohol limits – to be published
A final decision on the proposals is expected next year.