CCTV cameras caught a man with an 18in machete hidden in his trousers.
Police want to speak to the man, pictured, who was caught showing two other men the weapon at The Lifeboat Inn, Seafront, Hayling Island.
He was at the back of the pub, by the pool table.
PC Simon Smith said: ‘It is entirely unacceptable to carry a weapon of this nature around with you, and we are very keen to track this man down as quickly as possible.
‘If you believe you know who he is, please get in touch as soon as possible. This was a busy pub, full of customers so there is a good chance someone will recognise him.’
The incident took place on Saturday, July 30 at 9.30pm. Call police on 101.