The Chiss are a near-human species distinguished by their blue skin and glowing red eyes, which grew darker depending on the oxygen content of their surroundings. The more oxygen present, the more intense the color of their eyes and skin tone. Male and female Chiss tend to be more powerfully built when compared to Humans but exhibit the same variances as Humanoid sexes. A Chiss stands between either 1.6 to 2.1 meters in height though an average height of an adult is around 1.7 meters.

The fact that all Chiss often appeared in very good physical shape is an indication that the species possesses an active metabolism which is responsible for their trim figure. Beyond the obvious physical features, physiologically, the Chiss are similar to humans to the point that they possess comparable circulatory, neurological, digestive and reproductive systems.

In addition, they experience a greatly accelerated growth rate compared to humans, which contributes to their reaching maturity faster than humans. Thus a Chiss at the age of 10-years holds the physical maturity of a 20-year old Human. They are capable of living up to 80 years old, at which point a Chiss is considered venerable; children are between ages 1-10, and they experience a rapid adolescence from 11-12 and are considered full adults by 13-14.