Disabled people could be putting their lives at risk by buying do-it-yourself stairlift kits over the internet and installing them themselves, the British Healthcare Trades Association (BHTA) has warned.
The trend developed in the United States and the association is worried it will become popular in the UK.
BHTA director general Ray Hodgkinson said DIY stairlifts are "an accident waiting to happen" and while disabled people think they are saving money by buying on the internet, they will pay in the long-term.
"Stairlifts must be installed by experienced professionals or the results could be tragic," he said.
Steve Dickinson, managing director of stairlift manufacturer Bison, said stairlifts are complex pieces of equipment and not something that can be installed "by a relative, friend or DIY enthusiast".
David Jenkins, product safety advisor for the Royal Society for the Prevention of Accidents, said: "The implications of getting it wrong would not only be financial.
"There could be serious injury or even death."
A spokesman for the Disabled Living Centres Council said stairlifts should be fitted by a qualified engineer.
He added that while the internet is useful for finding information about specific products, disabled people should seek advice from one of the 50 nationwide Disabled Living Centres or contact their helpline* before buying.
*Disabled Living Centres Council helpline 0161 834 1044