When a change in rural land use occurs there is generally a period when considerable economic gains are made by those who take the high initial risk. Once viability of land use change is established this advantage tends to disappear. This study gives consideration to the economic viability of dairy conversion of land in forestry production, in the Central North Island of New Zealand, from 1999 to 2005. The physical feasibility of dairy conversion of forestry land is described and the financial viability of conversion in three consecutive time periods is investigated. Discounted cash flow methodology is used to determine return on investment in undeveloped land. Results of the financial models are then compared with prices paid in the market over the study period for developed dairy farms.