Iryn Rassat of Constitution Hill has been missing since April 25.
Police said there had been no word from him since and have appealed for information.
Mr Rassat, 68, was last seen about 1.30pm on Friday, April 25, in Parramatta, where he was supposed to meet his son.
Relatives reported him missing a few days later, when he did not return home to Constitution Hill.
Mr Rassat is described as being of Indonesian appearance, of slim build, 170cm tall, with short dark hair, a black and grey goatee and wearing a long-sleeved grey check shirt, brown trousers and black shoes.
Anyone with any information is urged to contact Parramatta police on 9633 0799 or Crime Stoppers on 1800 333 000.