It is endemic to the Philippines where it is found on Mindanao (including Mount Malindang), Basilan, and in the Sulu Archipelago.

[2] Occidozyga diminutiva is a small stocky frog, not exceeding 30 mm (1.2 in) in body length.

Toes are incompletely webbed and nostrils are lateral (these characters can be used to distinguish it from Occidozyga laevis with completely webbed toes and superior nostrils).

Males have a nuptial pad in their hands and paired subgular vocal sacs; with mean snout–vent length of 19 mm (0.75 in), they also appear to be smaller than females.

[3] Its habitats are streams and quiet pools of water in undisturbed and disturbed lowland forests.