This article is from the Hanggliding and Paragliding FAQ, by Joao Geada with numerous contributions by others.
Like any form of sport aviation, hanggliding can be dangerous if
pursued carelessly. That said, however, hanggliding can be a very safe
sport. Gliders in the US are now certified for airworthiness by the
Hang Glider Manufacturers Assn. (HGMA) so structural failures on
recent equipment flown within its placarded limits are a thing of the
past. In addition, reserve parachutes are used on all high altitude
hangglider flights now and provide a measure of safety in the rare
instances of severe glider damage or complete loss of control.
Also, hanggliding instruction has been standardized and most students
learn from certified instructors using a thorough, gradual training
program. So the days of untrained pilots trying unsafe maneuvers at
dangerous sites are also largely gone.
Despite these advances, people still make judgement errors and
aviation is not very forgiving of such. The bottom line is that out of
about 10,000 active pilots in the US, 5 to 10 will have a fatal
hanggliding accident in a given year and perhaps 10 times that many
will have an injury requiring treatment. The majority of pilots fly
their entire careers without sustaining a serious injury.