A member of staff at Thomson First Choice in Tonbridge was threatened during an armed raid.
Kent Police said four members of staff and four customers were in the shop in Tonbridge High Street when a man wearing a red wig, make-up and dark glasses entered.
The incident happened at about 9.10am on Saturday morning.
A police spokeswoman said the female manager of the store was threatened “verbally and physically” by the man who was carrying what appeared to be a handgun.
The robber, who was described as being in his 50s and of athletic build, left with cash and was seen running towards Angel Walk and Angel Lane. It is not known how much money was taken.
The thief, who is thought to be about 5ft 9in, was wearing a grey or white hooded top, black jeans, a dark-coloured jacket and gloves.
The police spokeswoman said: “Police are appealing to anyone who may have seen someone acting suspiciously in the area around the time of the robbery. They’re also appealing to any costume and fancy dress shop owners who may have recently sold a distinctive red wig.”
Anyone with information is asked to contact Kent Police on 101 with the reference number 0479.