Wainaku is located on the east side of the island of Hawaii at 19°44′50″N 155°6′3″W / 19.74722°N 155.10083°W / 19.74722; -155.10083 (19.747258, -155.100954).

[4] As of the census[6] of 2000, there were 1,227 people, 422 households, and 316 families residing in the CDP.

There were 453 housing units at an average density of 344.4 per square mile (133.0/km2).

21.1% of all households were made up of individuals, and 11.1% had someone living alone who was 65 years of age or older.

Media related to Wainaku, Hawaii at Wikimedia Commons