The paratriathlon is a variation of the traditional triathlon and consists of three events:

• 750 meter swim
• 20 kilometer bike (performed with either a handcycle, bicycle or tandem with a guide)
• 5 kilometer run (performed in either a racing wheelchair, prosthesis or along with a guide)

Paratriathlon was first held at the Paralympics as an official event in the 2016 Summer Paralympics in Rio de Janeiro, Brazil.

Athletes compete in categories based on their physical disabilities.

Para-Triathlete Wheelchair (PTWC) refers to wheelchair users, who use a recumbent handcycle on the bike course and a racing wheelchair on the run segment. Both PTWC classes compete in the same PTWC medal event in the Paralympics.

Para-Triathlete (PT) categories refer to those with physical impairments, such as athletes with impaired range of movement or amputee athletes who use approved prosthesis (for example, a specialty prosthetic leg known as a running blade) or other supportive devices during the bike and run segments. Each PT category competes in their own medal events—though, notably, not every classification category is contested at every Paralympics.

Para-Triathlete Visual Impairment (PTVI) categories refer to those who race with visual impairments. When racing in this category, one guide from the same nationality and gender is mandatory. During the race, they must ride a tandem bike during the bike segment. All VI classes compete in the PTVI medal event at the Paralympics

Currently there are nine sport classes:

PTWC1: Most impaired wheelchair users.

PTWC2: Least impaired wheelchair users.

PTS2: Severe impairments.

PTS3: Significant impairments.

PTS4: Moderate impairments.

PTS5: Mild impairments.

PTVI1: Athletes who are totally blind, from no light perception in either eye, to some light perception.

PTVI2: Severe, partially-sighted athletes.

PTVI3: Less severe partially-sighted athletes.

*** PTVI and PTWC categories, when they compete in one class in the Paralympics or world championship events a “factoring” system is used—ie. a head start is given to athletes with more severe impairments, based on a classification system.