The impact of oil pollution on seabirds has been widely reported in the ornithological literature. We reviewed the world-wide mortality of seabirds resulting from oil spills occurring from the 1960s to the present. Oil spills were classified as either 1) accidental, or 2) chronic. Among accidental oil spills from ships, oil terminals or pipelines, oil spills from ships were the commonest, with 43 events. Following the increasing use of supertankers for oil delivery, the spill volume from recent accidental spills sometimes outweighs the total annual spill volumes recorded during the 1970s. The spill volume of an event is only weakly correlated with the degree of impact on seabirds, as has previously been reported, because depending on the time of the year and the location, even a small amount of oil can have a great impact on seabirds, as was the case along the Norwegian coast in 1979. A few studies have estimated the total numbers of seabirds dying by taking into account the proportion of carcasses that sink, and the persistence rate of carcasses along coasts. Many studies have claimed that determining the impact of oil spills on seabird populations is fraught with difficulties, unless information on pre-spill status is available for targeted populations. Sources of chronic oil pollution include the discharge or dumping of oil polluted water or waste oils from ships, oil tanks or pipelines. Although chronic oil pollution has the potential for having serious impacts on seabird populations, it receives far less public attention than conspicuous accidental oil pills. For example, 7, 735 seabird carcasses were retrieved after the tanker Esso Bernicia spilled near a North Sea oil terminal in 1978, but more than half of these birds had actually died as a result of oil contamination from a chronic spill, and not as a result of the tanker spill. Beached bird surveys, and analysis of oil chemical composition attached to carcasses and beaches have played an important role in recognising the occurrence of chronic oil spill events and determining the source of the oil and, in some cases, in assessing their impacts on seabirds. In order to evaluate the areas, or seabird populations that are vulnerable to oil pollution, basic information on the distribution and ecology of each seabird species is also required. Such information has been lacking, especially for the seabirds that inhabit the seas around Japan. To help seabird populations recover after oil spills, it is necessary to remove those factors preventing a particular population from recovering, such as bycatch at sea, predation at the breeding ground and/or by making improvements to the breeding habitat.