This paper examines the relationship between bank lending rates and their cost of funds in New Zealand. Our results show that on average mortgage rates respond more quickly to changes in the cost of funds than base business lending rates. We also find an asymmetry in the initial (short-run) response of banks to changes in funding costs; in particular, our results show banks adjust mortgage rates downwards faster than upwards. The speed to which lending rates revert back to their equilibrium relationship with funding costs varies across the lending markets. We find the adjustment speed is faster when mortgage rates are below equilibrium, whereas it is slower when business lending rates are above long-run levels in relation to funding costs. Our analysis suggests that banks prefer the plain-vanilla type of lending such as mortgages in comparison to small business lending consistent with asymmetric information associated with business loans.