Research shows toddlers growing up in private rentals are less safe than children in other households, with lower rates of smoke alarms and more dangerous driveways.
The University of Auckland's Growing Up in New Zealand study has found almost 30 percent of private rentals do not have working smoke alarms, and more than 40 percent are not fully fenced or have separated driveways.
A researcher involved with the study, Sarah Berry, said there was significant room for improvement.
"Private rentals are in particular lacking for working smoke alarms," she said.
"So family-owned homes and state-owned homes are well-equipped for smoke alarms. Private rentals, not so well-equipped."
Ms Berry said because it was likely the numbers of families who rent would increase, it was important to bring private rentals up to scratch.