National residential rents rose 3.4 per cent annually to set a new record $460/week, according to Trade Me Property, which says about 11,000 places are advertised on its site each month.
Head Nigel Jeffries said a lack of rental housing supply had driven up asking prices for rents.
The situation was particularly acute in Wellington, he said, where available stock fell 71 per cent.
Trade Me said it compiles its report on renting from its own data, analysing properties advertised by property managers and private landlords.
Trade Me said last month that tenants had less choice.
Read more: Rental stock plummets: Auckland -35pc, Wellington -69pc
Today, it said the number of available properties in Wellington fell 71 per cent at the end of November compared to last year.
"We are seeing a growing number of enquiries on Wellington rental listings within just hours of appearing on-site. In November, a two-bedroom property in Mt Cook received 33 enquiries in the first three hours of being listed," Jeffries said.
In Auckland, available stock fell 35 per cent on last year, Jeffries said. But the median weekly rent only rose 1.9 per cent annually.
Christchurch is one of very few places in the country where the supply of rental properties was in good shape, he said. Rents there dropped 1.3 per cent to a median $390/week.
Latest data from Auckland property management firm Crockers showed the average rent for two-bedroom residential property increased slightly from $484 to $488, and the average two-bedroom rents across New Zealand decreased from $395 to $385.
"This has resulted in the Auckland two-bedroom premium to increase from 23 per cent to 27 per cent. The average rent for three-bedroom properties in Auckland has increased slightly from $612 to $618, while average rents across New Zealand increased from $450 to $460, resulting in the Auckland three-bedroom premium softening slightly from 36 per cent to 34 per cent," Crockers said.
"The recent release of the new valuations for Auckland city properties - with the associated expectations of increased rates - is likely to raise Auckland rents over coming months," Crockers predicted.
Data from one of Auckland's biggest property managers in October showed residential rents are rising as landlords face increasing costs.
Kiri Barfoot, a director of agency and management business Barfoot & Thompson, which manages more than 14,500 Auckland rental properties, said rents rose nearly 5 per cent throughout the city in the latest quarter, and by 6.2 per cent in the central suburbs.