Using freedom of information requests, the Tories found that about 2630 of the country's 7700 inmates have access to paid-for channels such as Sky Sports at an annual cost of £60,500.
The party last night claimed the perk was a blow to victims of crime and their families, and said access to blockbuster movies and Premiership Football showed life in prison was too easy.
However, the Scottish Prison Service (SPS) pointed out that no taxpayers' money was involved, as all the costs were met by prisoners paying £1 a week for the privilege and through charitable donations.
The cost of the TV sets was also recouped in full from prisoners, it said.
The service says having TV in cells can help to ease tension over Christmas, when prisoners cannot receive visits from their families, and reduces confrontations between inmates.
In 2010, the SPS ordered 1600 flat-screen, 19in TVs with in-built DVD players, allowing prisoners to watch more than 100 digital TV channels in their cells, including soft porn.
The service said it would have been too expensive to buy sets adapted to filter out porn.
MSP John Lamont, the Tory whip at Holyrood, said: "This will be galling for the thousands of law-abiding people who would like to be able to afford such luxury packages.
"There is a clear impression that modern prisons in Scotland are like holiday camps, and do little to rehabilitate, let alone punish.
"The concept of convicted criminals relaxing to watch festive films and the best sporting action will do nothing to banish that image.
"Instead of kicking back in their cells in front of The Muppets and An Idiot Abroad, prisoners should be given full-time work or training.
"That would actually give them a chance of a productive existence once released."
In a statement, the SPS said: "The cost of subscription television is met by contributions from the prisoners' Common Good Fund and the additional income from contributions from the prisoners' weekly charge for the use of in- cell television.
"The Common Good fund comprises donations made to prisoners or from 'profits' made from various goods and confectionery which are available to buy in prison. There is no cost to the taxpayer."