Research from the trade body shows there were 1,700 loans for house purchase in the region during the first three months of the year.
In comparison, the UK as a whole experienced a decline of 26% in loans for house purchase in Q1 compared to the previous quarter, but a less pronounced year-on-year decrease of 15%.
The CML says that given that the rush to purchase property at the end of 2009 due to the end of the Stamp Duty concession led to an artificially low level of lending in early 2010, the 23% fall in loans in Northern Ireland represents a substantial year-on-year decline.
Figures released today also reveal that there were 8,000 loans for house purchase advanced in Scotland in Q1, representing a 27% quarterly decline and a 19% annual decline.
Wales fared better compared to last year, with a quarterly fall of 26% but an annual drop of just 4%.