In a response to one online comment, it added: "It is not the vibe or environment we want to encourage here at Hawera Cinemas".
It seemed a majority of online comments were in favour of the dress code, saying it should be common sense.
"What happened to wearing clean tidy clothes for a evening out? PJs are bedwear only and gumboots are for farm wear," one commenter wrote.
Another added: "There is only one place to wear your PJs or jim jams, slippers and dressing gown and that is in your own home or garden, and certainly not after a certain time in the morning! It is just slovenly to wear these garments outside."
Just a friendly reminder that we have a dress code at Hawera Cinemas, it's simple really, as long as you are...
Posted by Hawera Cinema 2 on Friday, 20 April 2018
However others said it was "stupid" to tell people what they could and couldn't wear to the movies.
One person wrote: "What kind of unbalanced person is upset by what someone chooses to wear?! So let's just ban that form of expression and give everyone the same white cinema shirt at the door. Honestly, people get upset by seeing someone in pj's!? Not indoors!?... We now have a dress code to sit comfortably in DARKNESS and watch a film. Ludicrous."
And another pointed out that the cinema may risk losing customers, pointing out: "In an age where Netflix and On Demand services are taking over the film industry I don't think it's wise to define how people like to enjoy movies. By enforcing a dumb rule that doesn't affect anyone else will just motivate people to stay home where they can comfortably enjoy a movie how they want."
However, the cinema told RNZ it had not received any official complaints over the policy.
The story has been picked up everywhere from Australia to Slovenia and appeared on websites like the BBC, Mashable and The Guardian.
Hawera Cinemas posted on Facebook to thank everyone for their support and "hundreds of positive comments".
Wow! We are at a total loss for words! No way did we expect the reaction that we have received from our no...
Posted by Hawera Cinema 2 on Monday, 23 April 2018