The analysis indicated that ATS drugs, methamphetamine, and ecstasy were the predominant drugs of abuse in the area during 2005. Six of the 13 countries under analysis reported ATS drugs, in particular methamphetamine, as the primary drug of abuse. Nine of the 13 countries reported that methamphetamine abuse increased during the past year. The crystalline form of the drug was the most prevalent drug of abuse in Brunei, Japan, and the Philippines while the pill form dominated the markets in Cambodia, Lao PDR, and Thailand. However, law enforcement data showed significantly larger seizures of crystal methamphetamine in Myanmar and Thailand in 2005 compared with previous years, suggesting that the pattern of methamphetamine abuse in these countries may be changing. Seven countries reported a trend of increasing ecstasy abuse during 2005 and nine countries listed ecstasy among their abused drugs of national concern. Data on the seizure of crystal methamphetamine in Lao PDR and Cambodia during 2005 may indicate that crystal methamphetamine is spreading to other countries in the region. The primary drug of abuse in China, Malaysia, and Vietnam was heroin while Myanmar reported that opium was its leading drug problem. Australia and Indonesia ranked cannabis as the leading drug of abuse, while cannabis ranked as the second most prevalent drug of abuse in Brunei, Cambodia, Lao PDR, the Philippines, and Thailand. Benzodiazepines and ketamine abuse have increased in the region during the past several years and the abuse of inhalants and solvents continues to be an entrenched problem, particularly among urban street youth. Data were drawn from drug abuse control officials and institutions in Australia, Brunei, Cambodia, China, Indonesia, Japan, Lao PDR, Malaysia, Myanmar, the Philippines, Singapore, Thailand, and Vietnam through the internet-based Drug Abuse Information Network for Asia and the Pacific (DAINAP). Tables, figures, references, annex