The results of the fourth annual survey of entanglement of Antarctic fur seals at Signy Island,South Orkney Islands are reported for the 1999/2000 summer season. There were five sightingsof seals wearing neck collars of man-made debris. One additional sighting was of an animal that had been previously entangled but had lost its collar by the time of observation. All of the animals involved were juvenile males, the main component of the population at this time of year.The number of sightings was the lowest ever recorded, a decrease of 50% compared to the previous season. This was despite the fact that the number of fur seals arriving at Signy Island in 1999/2000 was the highest observed since entanglement surveys began in 1996/97. Data are compared with results from a parallel study undertaken at Bird Island, South Georgia in1999/2000. These indicated that the number of entangled fur seals had also decreased (by 42%) since 1998/99. Over the past four years, fluctuations in the incidence of entanglement between years at Bird Island have been mirrored at Signy Island. ‘Severe’ and ‘very severe’ injury was being caused to 60% of animals at Signy Island, which was the lowest on record. As usual this was higher (by 46%) than the proportion of fur seals sighted with the same injuries at Bird Island.This suggests that the majority of fur seals arriving at Signy Island had been entangled for sometime and had likely been entangled in other areas, such as South Georgia, where fishing activity is higher. Fishing net was the most common entangling material at Signy Island (60%) followed by packaging bands (20%) and a neck collar made of unknown material (20%). The proportion of animals entangled in packaging bands was the second lowest recorded, a decrease of 20% compared to the previous year. At Bird Island, packaging bands were the most common entangling material, increasing by 12.5% since 1998/99. The continued presence of packaging bands, despite the CCAMLR restrictions imposed since 1995/96, may be due to their persistence in the environment or illegal un-monitored fishing activity. The decrease in the incidence of entanglement at Signy Island and Bird Island is promising. CCAMLR needs to continue this monitoring and its campaign against the disposal of man-made debris at sea.