This paper examines downward price rigidity in Iranian house market and discusses whether this characteristic would result in an asymmetric relationship between house price and monetary policy. To test the downward house price rigidity the threshold GARCH model is employed. The asymmetric adjustment to monetary policy is examined using the asymmetric cointegration and error correction models. The results indicate the presence of the downward house price rigidity in Iranian house market. Moreover, house price are asymmetrically adjusted to monetary policy such that it is increased to reflect a loose monetary policy whereas displayed a large amount of persistency following a tight monetary policy. The results imply that house price tend to overreact in upturns and underreact in downturns reaffirming the downward house price rigidity in Iran. Hence, the government should consider the asymmetric house price adjustment when implementing relevant policies for the house market to avoid the creation of a bubble or the collapse of the house market.