The aim of this study was to provide an overview of the first year of the NSW Minimum Dataset for Alcohol and Other Drug Treatment Services data collection, including describing the patterns and correlates of people having received treatment in New South Wales. All closed treatment episodes for the 2000 – 2001 financial year were included for descriptive, univariate and multivariate analyses. There were 33 459 closed episodes of care in New South Wales in the 2000/2001 financial year. The majority of clients (69%) were male and the mean age was almost 34 years. The majority of treatment is sought for problems related to alcohol (37%) and heroin (33%) use. More than a third (40%) of clients were new to drug and alcohol treatment. Half the clients had a history of injecting drug use with 6.3% of those with heroin as their principal drug of concern, never having injected. The most common main service provided was in-patient withdrawal (26%). Multivariate logistic regression revealed that being older, not homeless, non-indigenous and having heroin as the principal drug of concern predicted receiving out-patient withdrawal management. Analyses of length of stay in residential treatments and number of service contacts in non-residential treatments are reported. The NSW MDS AODTS is a critical information source for policy development, service planning and surveillance. The results of this paper illustrate the utility of the data collection for identifying emerging issues in the patterns of drug use and service delivery for clients with alcohol and other drug problems.