The 11 cities are Barcelona, Copenhagen, Dublin, Geneva, Hamburg, Helsinki, Lisbon, Oslo, Paris, Rome, and Stockholm. Almost all of the cities provided data on treatment demand, drug- related deaths, and police arrests. All provided data on seizures of drugs, although four could do so only at the national level. The availability of data on other indicators was more varied, reflecting differences in data-gathering priorities and practices in the different cities. In just over half the cities, treatment demand increased between 1989/90 and 1992; in the rest of the cities it was stable. On the basis of partial data, apparently hepatitis B was low and usually declining. In about half the cities, the number of drug-related AIDS cases were stable; and in the other half, they were increasing. The number of drug-related deaths between 1989/90 and 1992 increased in Lisbon, Oslo, and Rome, fell in Copenhagen and Hamburg, and remained stable or variable in the other cities; however, in 1993 in five of the six cities where data were available, the numbers declined. In half of the cities, police arrests for drugs increased in the past 3 to 4 years. Data are also provided on the number of people sentenced to imprisonment for drug offenses, the quantity of drug seizures, and the price-purity of various drugs. 4 tables