The Tropenbos programme aims at developing common methodologies to inventory and evaluate humid tropical forestland. Such methodologies enable the comparison of results of land inventories obtained at the various Tropenbos sites. To maintain comparability of these data and results a standard database was developed for data storage. The result is the TROFOLIN (TROpical FOrest Land INventory) database. QRay Agrimathica, Veenendaal developed the model, which underlies the database, in co-operation with the Winand Staring Centre, Wageningen. The present TROFOLIN Database User Manual provides guidelines for the installation of the database at the user's personal computer as well as a step by step explanation of its actual functions, options and operation. In addition, the manual offers some guidelines to work with TROFOLIN data through the database package dBASE.