Technical Abstract: No-till has been shown in field trials and in practice to improve soil conditions and water quality, as compared to conventional tillage methods. However, studies of the relative economic impacts of no-till farming have generally been inconclusive. For the most part, this inconclusiveness is due to the fact that grain yields may decrease initially, and then rise after farmers switch from conventional tillage to no-till. Some studies, but not all, suggest that long term yields under no-till are often higher than under conventional tillage. To help farmers make informed decisions about tillage alternatives, more conclusive information about the farm-level economic impacts of tillage alternatives, particularly no-till, is needed. In the present study, data pertaining to the Fort Cobb Reservoir watershed (FCRW)in southwestern Oklahoma was used to evaluate the farm-level economic impacts of no-till farming as compared to conventional tillage as well as the current mix of prevailing tillage practices in that part of the state. Farm-level Economic Model (FEM), an annual economic simulation model, was used to determine the impacts of the alternative tillage practices on farm profits under various diesel price and winter wheat yield scenarios. While the emphasis was on winter wheat, alternative tillage simulations were performed for all applicable crops grown in the area. The results of the present study indicate that if winter wheat grain yields are identical among tillage systems, no-till would be more profitable than conventional tillage or the current mix of tillage practices in the watershed. Even if the switch from conventional tillage to no-till results in a small yield penalty (about 5%), no-till would still be more profitable even at reasonably low diesel price levels. However, if there is a significant winter wheat grain yield penalty associated with no-till (10% or greater), no-till would no longer be as profitable as conventional tillage or the status quo, even at reasonably high fuel prices. The relative financial performance of no-till farms is thus highly dependent on crop yields. While these results are based on data collected in the FCRW, they are readily applicable to other areas in western Oklahoma.