After more than 30 years of intensively collecting, describing and studying agarics in the Netherlands, both by professional and amateur mycologists, it was felt that the time had come to endeavour the publication of a critical Agaric Flora of the Netherlands, in order to make the accumulated data on taxonomy, ecology, phenology, and distribution of Netherlands’ agarics available to everyone interested in any aspect of the agarics. In spite of the work on agarics up to now done in the Netherlands, the many recent (but often conflicting) publications in Europe, and the rather limited agaric flora of the Netherlands (the total number of species being estimated at 1600), this is certainly not a mean task, if ‘critical’ as used above is taken to mean that (i) this Flora, as much as possible, be based on original observations, (ii) all taxa, although often to be treated by different authors, be rather extensively described in an entirely comparable way, (iii) the habit and the most important microscopical characters of each species be illustrated, and (iv) the most recent edition of the International Code of Botanical Nomenclature be closely followed.