Atmospheric greenhouse gases, including carbon dioxide (CO₂), methane (CH₄), and nitrous oxide (N₂O), purportedly lead to global climate change due to their increasing concentrations. Agriculture has been identified as one of the major sources of greenhouse gas emissions. Although the Midwestern United States is one of the world's major agricultural production regions, few research data are available to assess the possibly interacting effects of tillage and rotation practices on greenhouse gas emissions. The objectives of this study were to assess (i) the short-term effects of chisel (CH) and moldboard plow (MB) on CO₂, CH₄, and N₂O emission and (ii) the temporal variability of gas emissions (long-term effects) due to CH and MB tillage treatments relative to no-till (NT) in continuous corn (CC) and corn-soybean (CB) rotations systems. This tillage experiment has been conducted on a dark prairie mollisol in West-Central Indiana for 30 years. For short-term tillage effects, gas emission was measured immediately before tillage and at 0, 1, 2, 24, 48, 72 and 168 hrs after tillage while long-term effects were evaluated by measuring fluxes weekly for 22 weeks. All gas emissions were measured from the soil surface using vented flux chambers. Tillage treatments significantly increased CO₂ and N₂O emission but had relatively little effect on CH₄ flux. In the short-term, emissions increased immediately after tillage but decreased with time. Mean CO₂ emission ranged from 75 mg m^-2 hr^-1 for CBPL to 1,637 mg m^-2 hr^-1 for CCCH while N₂O ranged from -0.19 to 0.27 mg m^-2 hr^-1 for CCCH and CBCH, respectively. Gas emission during the growing season was highly variable with peak fluxes occurring in June. On average, CO₂ and N₂O emissions were significantly greater for CH treatment (4432.2 and 1.95 mg m^-2 hr^-1, respectively) relative to both MB and NT in both rotations while N₂O emission was lowest for CBNT. Long-term chisel plowing may contribute more to greenhouse gas effects than either moldboard or no-till and continuous corn emits more greenhouse gases from the soil surface than corn-soybean rotation systems.