The latest buy-to-let index from Your Move found that average residential rents have climbed 0.6% in the year to April 2016, the slowest annual rise seen since March 2013.
It represents a “significant downturn” in rates of year-on-year growth from the 1.1% recorded in March, and 2.1% in February, the report found.
Average rents in Scotland now stand at £542 per month, following a 0.4% monthly fall in April.
This is the lowest they have been since they touched £539 in April last year.
Despite the wider slowdown across the country, Your Move said the annual rent rises in Edinburgh and the Lothians “continue to accelerate”, reaching a peak pace of 10.5% last month.
The jump has taken average monthly rents in the region to a record high of £651, up a considerable £62 from a year ago, the report found.
Brian Moran, lettings director at Your Move Scotland, said: “Tenants looking to rent a property now may find themselves able to bag a bargain, after a slight spring slump in rent growth. Rents haven’t risen at such a leisurely place for three years.
“However, this year-on-year snapshot hides the many price fluctuations we’ve seen in between this April and last, and also isn’t uniform across the country.
“The lettings market is always at the mercy of local supply and demand, and in Edinburgh and the surrounding areas we’re seeing extraordinarily fast rent rises, as tenant competition shines brightest around the glow of the jobs market.”