Originally Posted by Kiwi Flyer
Not only possible but compulsory if you have both US & NZ passports. As with most countries, if you have a local passport you must use that one to enter and exit.
On the forms though they have a box for "New Zealand citizen traveling on another passport" or something like that, and I've done that myself before after I let my NZ one expire and got it redone in NZ after I entered the country on my US passport. I think I did have to leave on the US passport that time. Also my brother uses his US passport to enter NZ all the time and just checks that box.