In the United Kingdom (UK) and elsewhere, little is known about problematic drug use among older people (defined here as aged 50–74 years), either because few older drug users exist or because they represent a ‘hidden’ population. In this paper, we show that the average age of drug users in contact with treatment services and agency-based syringe exchange programmes (SEPs) in the counties of Cheshire and Merseyside in northwest England is rising. Between 1998 and 2004–05, the number of older male drug users in treatment increased from 80 to 310, and the number of older females rose from 46 to 117. Consequently, the median age rose from 30.8 years in 1998 to 34.9 years in 2004–05. Similarly, between 1992 and 2004, the number of older injectors accessing SEPs increased from three to 65 men and from one to nine women. The median age of SEP attenders was 27.0 years in 1992 and 34.9 years in 2004. Drug use amongst older people is associated with poor physical and psychological health and longer hospital stays. The future cost of the ageing of drug users may be considerable. Detailed research is needed to identify the characteristics and health needs of this vulnerable population.