Rather high prevalence rates of alcohol abuse in the elderly have been reported in the literature. However, there is some evidence that many elderly persons with alcohol problems are not identified, probably due to the nonspecificity of alcohol-related presentations in old individuals. Thus, there is an ongoing discussion on appropriate diagnostic criteria for alcohol dependence in elder people who frequently begin to abuse alcohol in late life. This study was aimed to explore whether alcoholics with late onset (beginning after the age of 45) differ from those with an early onset (prior the age of 25). Two hundred and sixty eight subjects consecutively referred to a ward of a general hospital specialized for alcohol detoxification were divided into three groups by the age at onset of harmful alcohol consumption. The duration of harmful drinking was rather similar in all groups. However, alcohol dependence according to the ICD-10 criteria (three or more have to be fulfilled) was diagnosed in 94.1% of the alcoholics with an early onset (≤ 25 years), but only in 62.2% of those with late onset (P < 0.0001). Significant differences between these groups were found for the following criteria: preoccupation with drinking (P < 0.0001), impaired capacity to control drinking (P < 0.01), strong desire to drink alcohol (P < 0.01), and a trend towards a lower rate of lifetime psychiatric comorbidity. The alcoholics with late onset reported fewer previous detoxifications and a lower actual alcohol consumption. Moreover, they showed a higher rate of abstinence in the 12 month follow-up. Regarding the difficulties in comparing groups of different ages at onset of harmful alcohol use our results suggest that the alcoholics with late onset differ in many ways from those with early onset.