Pelophryne guentheri has only been seen a few times since its description in 1882. It must be considered a rare species, known at this point only from the Matang range of Sarawak. However, further research might discover it elsewhere.

This species grows larger than
P. api, P. saravacensis, and P. signata. It has very long arms and a small head. Note the extend of webbing between toes and fingers and the truncated, nearly rectangular finger tips.

Size of adults: approx. 25 mm snout-vent length.
Where this species deposits its eggs, how many eggs there are in a clutch and whether the development is through a feeding or non-feeding tadpole... All these questions remain unanswered and need further research.

We observed males calling from trunks of large trees 1-5 m above ground in a kerangas-dipterocarp transition zone. This species is very similar to
Pelophryne saravacensis, which, however, calls from saplings.