In a first of a kind, grass roots plant of the complexity of the Great Plains Gasification Plant the lessons learned are numerous and encompass a wide range of items. This report documents the lessons learned from all phases of the project from preliminary design through the most recent operation of the plant. Based on these lessons learned, suggestions are made for changes and/or process improvements to future synfuel plants. In addition, recommendations are made for research and development in selected areas. 46 refs., 31 figs., 33 tabs.