The Deepwater Horizon spill was one of the largest oil spills in recorded history, depositing more than 2.6 million gallons of oil a day over the course of 84 days into the Gulf of Mexico, and with it considerable unprecedented problems and concerns. With an eventual total of 172 million gallons leaked into the Gulf, the Deepwater Horizon spill disrupted the ecology and deeply affected wildlife populations along 690 miles of U.S. coastline. The Exxon Valdez oil spill of 1989 resulted in the release of 10.8 million gallons of oil in Alaska. Comparatively speaking, however, the quantity of oil released from Deepwater Horizon was the equivalent of an Exxon Valdez spill happening every four days for three straight months. Although the volume of oil spilled from the Exxon Valdez tanker represents only a small fraction of that from Deepwater Horizon, Exxon Valdez cleanup efforts took decades and the effects of the spill on wildlife are still being observed today. While both disasters involved crude unprocessed oil, there are many factors that distinguish these two events. Oil spills, though generally involving similar compounds, often have unique characteristics and consequences, each depending on its environment, the nature of the spill, and many other natural factors. This review surveys the general environmental and toxicological effects and implications of oil spills, with particular emphasis on the unique aspects of the Deepwater Horizon spill.