The woman was among a group climbing near Whangaehu Hut, on the eastern side of the mountain, on Saturday.
Police said the woman slipped and fell down a slope about 11am.
She fell "a significant distance, suffering serious injuries", police said.
"Emergency services, the Greenlea Rescue Helicopter, members of the Ruapehu Alpine Rescue Organisation, and Tukino Ski Field staff, responded immediately.
"Sadly, despite their best efforts, the woman died at the scene."
A rāhui was in place on the eastern slopes of the mountain above 2000 metres, until 6am Tuesday.
Sergeant Shane McNally called it a "tragic incident".
"While the matter is still under investigation, we cannot reiterate enough the importance of understanding the alpine environment and being prepared mentally and physically for this unforgiving environment."
