Some of the most popular scenic areas are being left strewn with piles of litter, including human waste, and suffering damage to natural habitats.
The issues, which have escalated since the Covid pandemic began, are causing widespread concern.
As well as being an eyesore, dropping rubbish is a criminal offence and can cause harm to wildlife and people.
The country’s environmental watchdog has highlighted the dangers of discarded trash.
A spokeswoman from the Scottish Environment Protection Agency (Sepa) said: “Compliance is non-negotiable.
“The inappropriate disposal of human waste and litter is not only unsightly, but, depending on the nature of the waste, can also be hazardous to the health of both humans and animals as well as causing environmental damage.
“It is a criminal offence to illegally dispose of waste and the responsible parties could be subject to enforcement action.
“Everyone can do their bit to help end the selfish dumping behaviours that blight our communities by taking responsibility for their waste and disposing of it in an appropriate manner.”
Stuart Chalmers, national visitor services manager for Forestry and Land Scotland, said the sheer numbers of folk turning up at the most popular places is the main cause of many of the problems.
“In general people behave very well,” he said.
“Probably 98 per cent of people are responsible, but it’s that small proportion that are spoiling places for everyone.”
Prime examples are the country’s two national parks, which experienced a major influx of visitors during last weekend’s bank holiday.
In the Cairngorms, loads of litter was left behind after more than 50 tents were pitched at Loch Morlich in Glenmore forest.
There were also issues with unburied human excrement, despite toilet facilities on the site.
Meanwhile, rangers in Loch Lomond and the Trossachs collected 15 bags of rubbish which had been dumped beside overflowing bins at the base of Ben Lomond.
Mr Chalmers said: “Genuine wild camping is fine, where burying your waste is the right thing to do.
“But it seems some people were camped quite far from the public toilets and were too lazy to walk all the way there.
“We’ve had to bring in specialist companies to clean up after them and that’s a costly operation.”
Zero Waste Scotland (ZWS) has recently launched a second phase of its anti-littering campaign Scotland is Stunning – Let’s Keep It That Way.
Iain Gulland, chief executive of ZWS, said: “As restrictions ease and many of us can once again return to our favourite Scottish beauty spots, we are asking everyone to take their litter home or bin it.”
He added: “Now is the time to enjoy the great outdoors, but please leave Scotland as stunning as it was when you found it.”
Surveys by ZWS show nine out of ten Scots see litter as a problem in their area, while one in three have reported an increase since the Covid pandemic began.
Some of the most visited locations have increased their toilet facilities and taken on countryside rangers to help combat the problems, while a new network of campervan stop-over sites is also being launched in the Highlands.