The vast majority of ScotRail services are cancelled today as RMT members at Network Rail take fresh strike action across Britain.
The massive disruption is likely to cost Scottish firms millions of pounds in lost business and additional costs.
Tourism and hospitality are among sectors worst hit by the latest walkout at the height of the holiday season.
The Scottish Licensed Trade Association has highlighted the negative affect of the continued industrial action.
SLTA managing director Colin Wilkinson said: "Rail operators have confirmed that they will run just 20% of normal services across only half of the UK network, with trains operating for just 11 hours, between 7.30am and 6.30pm.
"This means the last services from London to Scotland will leave in the early afternoon, throwing the plans of tourists and people on business into disarray."
He added that the lack of trains would not only put off customers from visiting hospitality, but would also have an impact on staff being able to get to work, with the Edinburgh International Festival, Fringe and other events in Scotland coming soon.
What message are we sending tourists?
Mr Wilkinson said: "Tourism is getting a boost from visitors from overseas and across the UK, but what message are we sending them if they can't catch a train to get to where they want to go?"
The north-east is particularly badly hit by today's strike as ScotRail will only be providing five services - all in the central belt.
North-east businesses are angry that ScotRail is not running any trains to or from the north-east today.
Fergus Mutch, policy adviser at Aberdeen & Grampian Chamber of Commerce, said "If ScotRail has capacity to operate a skeleton service, it's not good enough for this to be just in the Central Belt."
Around 40,000 RMT members across Britain have walked out today, and are to continue their action on August 18 and 20.
ScotRail is also expecting disruption tomorrow morning caused by the closing and reopening of signal boxes at different times across the country.
The walkout by staff at Network Rail and 14 train-operating firms is part of a continuing row over pay, jobs, and terms and conditions.
The RMT dispute does not involve ScotRail staff, but will still mean a major reduction in services.
It follows a similar strike last month which saw rail services severely disrupted across three days.