This report documents the results of a countrywide survey by county for Aedes aegypti (L.) mosquitoes found breeding in drums in Trinidad, West Indies. The island-wide mean number of positive drums was 8.1 +/- 2.9 per county and the mean number of positive drums per house was 3.0 +/- 0.7 and ranged from 1.6 in St. George East to 4.9 in St. Andrew/St. David. The Breteau index varied from 6.2 in St. Andrew/St. David to 52.5 in Victoria East, with the median figure of 29.5. The most common location of drums was under the eaves of houses (71.4%) in eight out of nine counties surveyed, and a high proportion (82.3%) was positive for Ae. aegypti at this location. Water stored in drums was used primarily for washing clothing (57.5%), with 6.6% for drinking, 12.9% for bathing, and 23.0% for miscellaneous purposes. An average of 68.4% of all drums at the nine sites were uncovered and were located under the eaves of houses, with 76.2% being filled under the eaves by rainfall. Tanks were the main potable water storage container found in all nine counties, with a mean number of 1.4 +/- 0.6 per county. In our survey, all water drums were treated as if they were for potable use, but this had virtually no correspondence with the actual findings in each county per household. We conclude that vector control strategies based on insecticide treatment and source reduction need to be revised in light of the current findings.