The Black Caps were looking for a morale-boosting performance after being thrashed in back-to-back away series by South Africa and Australia in the past two months.
Instead, the international minnows further dented their confidence, wrapping up the match with three overs to spare.
The New Zealand XI included five members of the squad to face Bangladesh in a series of three one-day internationals starting Wednesday, and another five with international experience who are pushing for a recall.
The match was organised to raise funds for victims of Cyclone Sidr, which killed at least 3,200 people and destroyed more than a million homes when it struck Bangladesh last month.
New Zealand, sent in to bat first, struggled throughout their 20 overs and could only post a modest 133 for seven.
Former international James Marshall top scored with 33 and Scott Styris made 29, while opening bowler Shahadat Hossain returned the impressive figures of three for 15 off four overs.
The New Zealand score was helped by Peter Fulton (3) and Ross Taylor (15) surviving appeals when television replays indicated they were caught behind.
Bangladesh made easy work of the run chase, scoring 134 for six in 17 overs.
Farhad Reza was caught behind for 31, Saqibul Hasan and Shahadat Hossain both made 22, while both Mohammad Ashraful and Aftab Ahmed were run out for 20.