The owner of the popular Irish pub J.B. O'Reilly's in Leederville is seeing red after the WA Health Department told him to remove his tobacco memorabilia signs or face prosecution and hefty fines.

Almost every inch of the popular watering hole in Cambridge Street is littered with antique signs and memorabilia, including a number of collectable tobacco signs dating back more than 120 years.

But the "advertising" has been deemed a breach of the Tobacco Act even though most of the brands are no longer available to purchase and ironically, despite the fact that J.B. O'Reilly's doesn't sell any tobacco products in the pub.

J.B. O'Reilly's owner Paul North told WAtoday on Thursday he was gobsmacked when a letter arrived from the department telling him to pull down his 25 vintage smoking signs.