Police are urgently appealing for any sightings of 34-year old Lauren Hamilton, of Tauranga.
Ms Hamilton recently gave birth, and is believed to have her newborn with her.
In a statement, police say they "are extremely concerned for the welfare of Lauren and her baby".
"We would like to hear from anyone who has seen Lauren in the last few days, or anyone who has information about where she might be.
"If you can help, please call 111 immediately."