Modern forestry increasingly often requires consideration of ecological objectives in planning calculations. A common problem in the integration of ecological objectives with forest planning is the lack of empirical models usable when evaluating the ecological merits of alternative forest treatment schedules. With respect to the habitat requirements of a threatened species, for example, the information might only be descriptive and scattered in numerous different case studies not directly exploitable with the forest area in question. A natural approach to alleviate these problems is to use existing ecological expertise in the form of expert judgments. This paper considers different possibilities for utilising ecological expertise in multi-objective forest planning through some practical examples. Special attention is paid to methodological issues concerning the collection and analysis of expert judgments. It is concluded that the modelling of ecological expertise is a useful tool in forest planning, but the inevitable uncertainties of expert judgments and the special pitfalls in modelling of expertise-as discussed in the paper-should be taken into account.