Holothuria leucospilota is a medium-sized sea cucumber reaching a length of up to 40 centimetres (16 in) when relaxed but it can stretch to about a metre (yard) when extended.

[3] A study done near Singapore found that Holothuria leucospilota was more common near boulders, corals and seaweed clumps than it was on the open seabed.

Holothuria leucospilota is a scavenger and when feeding it usually has its posterior end anchored underneath a rock or in a crevice so that it can contract back out of sight if disturbed.

[4] If threatened, Holothuria leucospilota can emit a mass of fine sticky Cuvierian tubules from its anus which ensnare the potential predator allowing the sea cucumber to escape.

[5] The worm pearlfish (Encheliophis vermicularis) is a parasite of this species and each parasitised H. leucospilota will host a male and female pair of the fish which live inside its body.