House sales in Northern Ireland during the three-month period from April to June were at the highest level recorded since the 2007 property crash.
However, the average price is slightly down, falling by 1.1% over the quarter.
The figures were published in the Ulster University's latest Quarterly House Price Index report.
It suggests the "mixed picture" could be influenced by a range of factors, including political uncertainty over Brexit and the stalemate at Stormont.
The report was compiled by Ulster University, in partnership with the Northern Ireland Housing Executive and the Progressive Building Society.
It found that the average house price now stands at £148,500. The figure has fallen by 3.7% over the year.
But the 2,372 house sales recorded between April and June meant the quarter saw the highest rate of property transactions in a decade.
"This latest survey has mixed messages regarding the health of the Northern Ireland housing market," said the report's lead researcher, Professor Stanley McGreal.
"Transaction levels are high suggesting a strong market in the second quarter of 2017, however, this optimism is not reflected in average prices which are generally more subdued," the Ulster University academic added.
Progressive's deputy chief executive, Michael Boyd, said: "There is no doubt that wider economic and political factors are having an impact including uncertainty following the triggering of Article 50, wage growth lagging behind inflation and the potential for the rise in interest rates."
But he added that there was still "confidence" in the housing market, as Northern Ireland remained "one of the most affordable regions of the UK".
(BBC news article)