The species is endemic to the islet Round Island, Mauritius, and typically dwells on palm trees.

The Round Island day gecko feeds on insects and nectar.

The specific name, guentheri, is in honor of German-born British herpetologist Albert Günther.

Males can reach a total length (including tail) of about 30 cm (12 in), but often are much smaller.

Since much of the original vegetation is destroyed, by tropical cyclones, P. guentheri is forced to live in rocky crevices.