MoRST is performing an evaluation of the funds invested in environmental research. The two case studies discussed in this paper contribute to the ongoing decision-making about this investment. Substantial funds have been invested in both research programmes identified. Because the main benefits associated with research output are environmental, they are difficult to value monetarily. Preliminary analysis suggests that at a discount rate of 6%, annual future benefit flows of $7 - $10 million will justify the water quality/clarity research. The expenditure on possum biocontrol will be justified if the research generates an annual future benefit flow of $20 million.