An activity oriented stochastic computer simulation model of forest biomass logistics in Greece, based on SLAMSYSTEM simulation language, has been developed. A SLAMSYSTEM simulation network was built to represent forest biomass units flow from felling to storage at a millyard. A simulation experiment with data collected at the Elatia forest region of Drama in North Greece was executed. Several scenarios of the observed and alternative inventory times, interest rates, and operational systems for forwarding, were used to define the effect of inventory time, interest rate, and loss of value due to fibre deterioration and operational systems, on cost per unit per operational stage, and the final cost at the millyard. The model may be used as a prototype Decision Support System for forest biomass logistics in Greece. Copyright (C) 1996 published by Elsevier Science Ltd.