One thousand respondents were asked by UMR Research if they believed "that Earth has been visited by UFOs from other planets".
About 33 per cent said they did, and Maori (42 per cent) and Pasifika (40 per cent) were more likely to believe.
The number of believers is greatest among the 30 to 44 year olds at 36 per cent, and drops to 26 per cent among those aged 60 and over.
Graeme Opie, a sighting investigator and researcher for the Ufocus New Zealand Research Network, said: "According to reports, the number of Americans that believe in extra-terrestrials and life on other planets is quite high too, so it isn't too surprising that many of us here believe in UFOs."
The veteran Hamilton traffic controller and pilot adds, "I can say with near certainty that UFOs have been to Earth ... and there's plenty of literature to back this belief."
Sightings in New Zealand include events such as the Kaikoura lights, the Ngatea landing-site mystery and the Gisborne UFO event of the late 70s that included sightings of silver-suited humanoids in the Waimata Valley.
The UMR survey also found 55 per cent believed that at least some people have psychic powers such as ESP.
Women (67 per cent), over-60s (63 per cent) and Maori (60 per cent) more likely than others to be believers.
Six in 10 - 72 per cent of women and 52 per cent of men - believe in the existence of God or a universal spirit.
Nearly 8 in 10 believe that Jesus was a real person who lived 2000 years ago, and 57 per cent believe in life after death. That belief declined with age, falling from 65 per cent among under-30s to 49 per cent among over-60s.
A quarter believed astrology can predict people's futures.