Introduction: While I’m sure most religions do not particularly like the tradition of Halloween, I thought it would be good to explain why Halloween is not good according to Theravāda Buddhism. Celebrating Halloween in modern times, regardless of the reasons why it was started in the first place, consists of dressing up in costumes. In celebration, you either dress up or you praise other people’s costumes. It is mostly bad karma for the one dressing up and if you praise that, it is not good either.