Objectives: to obtain a biomedical oral profile of a community of adult drug addicts in treatment by analysing their dental health, with a view to determining whether the state of their oral health could be attributed primarily to their lifestyle and the direct consequences of drug abuse on their overall condition, rather than to the effects of the drugs used. Experimental Design: the study was conducted under the terms of an agreement between the Complutense University of Madrid's (UCM) Odontology Faculty and the City of Madrid's Substance Abuse Institute. Seventy drug addicts and 34 control group subjects were examined. The study assessed oral hygiene habits, systemic pathology, type of drugs used and the duration of use, oral pathology, oral health indices, risk of caries based on saliva tests, oral candidiasis and periodontal microbiology. Results: statistically significant differences (p<0.05) were found between the test and control groups for practically all the variables analysed. In the drug users group, dental hygiene was wanting, systemic and oral pathology prevailed and the decayed/missing/filled teeth or surface (DMFT/S) indices denoted very poor buccodental health. The saliva tests showed a substantial risk of caries and candidiasis rates were high. By contrast, with a single exception, the microbiological studies detected no statistically significant difference between drug users and control groups periodontal flora. Conclusions: drug-dependent patients had poor oral health and a significant increase in oral pathology, essentially caries and periodontal disease. Their risk of caries was high and the presence of candidiasis was representative of their poor general and oral health. Drug users' poor buccodental condition was more closely related to lifestyle than to drug abuse itself.