This chapter examines the relative attractiveness of Kyoto project mechanisms as an option in corporate strategy to meet greenhouse gas emission targets. The analysis employs a transaction cost theory approach in combination with perspectives of institutional theory in organisational analysis. Empirical evidence is given from a study of climate strategies of Swedish companies. The analysis indicates that participation in the Kyoto project mechanisms is less attractive than other options. These mechanisms do not provide companies with the legitimacy they need to obtain other resources, and they are associated with transaction-specific costs that are too high to be viable alternatives.