During recent years harvested wood products (HWP) have received growing attention because they may be included in national greenhouse gas (GHG) inventories and possibly Kyoto Protocol (KP) accounting procedures in future commitment periods, with practical and economic consequences for both reporting and timber markets. The Intergovernmental Panel on Climate Change (IPCC) has identified three approaches to estimating and reporting carbon (C) stock in HWP; the stock-change approach, the production approach, and the atmospheric-flow approach. Should countries choose to report C stocks in HWP, one approach needs to be universally agreed for consistency. Using a model, the C stock both in use and in solid waste disposal sites (SWDS) at a national scale in Ireland was estimated and compared for the period 1961-2003 with uncertainty in the estimates generated using a Monte Carlo analysis. In 2003, the stock-change approach yielded the highest C sink, relative to the IPCC default approach of 375 Gg Cyr(-1) +/- 40% with the production approach and atmospheric-flow approach estimating the stock change at 271 Gg Cyr(-1) +/- 48% and 149 Gg Cyr(-1) +/- 31%, respectively. On the basis of the model results, the implications of selecting one approach over another and the contribution HWP may have in the future to help Ireland reach its reduction target under the KP are discussed. (C) 2005 Elsevier Ltd. All rights reserved.