The average monthly costs for buying a house in Scotland stood at £524 in December 2012 as opposed to £558 for renting a similar property.
Over the past 12 months the gap between buying and renting has widened by £19 per month according to the lender.
It says the substantial improvement in the affordability of buying relative to renting is largely due to a 38% decline in home buying costs over the past four years.
Nitesh Patel, housing economist at Bank of Scotland, said: "In the past few years, the sharp decline in home buying costs, combined with an increase in rents, has greatly improved the financial attractiveness of buying a home.
“This shift has contributed to the increase in the number of house purchases in Scotland in 2012.”
Scotland reported a 4% increase in the number of house sales in 2012. Nonetheless, sales, at 74,000, were still 50% lower than in 2007
However the data suggests that many people still have concerns about getting onto the property ladder.
Job Security (66%) and difficulties raising a deposit (46%) were seen as the main barriers to buying a home.
Patel added that despite concerns prospective homebuyers should remember that once they are on the first rung of the ladder their monthly costs could be notably lower.