Deputy First Minister Nicola Sturgeon said the money would make homes "warmer and cheaper to heat".
But in a report last week, environmental charity WWF Scotland said more than £6 billion is needed for Scotland to achieve its commitment to end fuel poverty by 2016.
While it welcomed the money, WWF Scotland said the £6m "falls well short of what is required".
Ms Sturgeon said the funding would go towards loft and cavity-wall insulation, under the Universal Home Insulation Scheme.
In addition, up to 35,000 people will be able to get a £500 voucher to contribute towards the cost of making their home more energy efficient. People can apply for the vouchers from next month.
Ms Sturgeon made the announcement as she visited a Lochfield Park Housing Association home in Easterhouse, Glasgow that has recently had insulation fitted.
She said: "With temperatures dropping, households across Scotland will be worrying about their winter energy bills.
"That is why we have ploughed an additional £6m into providing up to 10,000 households with free insulation and invested millions into a cashback voucher scheme that is due to go live later this week.
"This is the kind of vital help which can make a real difference to those struggling to make ends meet and demonstrates we will do whatever we can within devolved powers to tackle fuel poverty."
These efforts are being held back by the, "punishing price rises imposed by energy companies", she said and demanded more action from Westminster to tackle this.
"The UK Government, which has responsibility for this area, is simply not doing enough to regulate the market, and this has to change urgently."
According to WWF Scotland, some 800,000 households in Scotland are in fuel poverty.
Elizabeth Leighton, a senior policy officer with the charity, said: "The £6m will go some way to plugging the gap this year but, in the long term, our research shows that the Scottish Government needs to double its funding for fuel poverty and home energy efficiency."