Warrant Officer November Filander said the man was arrested following a tip-off at about 09:00 on Thursday.
"When police executed the search warrant at Dublin Mews, situated in Dublin Street, Woodstock, they recovered a 9mm Browning pistol, 178g of tik, 120 Mandrax tablets, 80 units of heroin, 70 units of cocaine, one parcel of dagga, 75 different rounds of ammunition, four MK8 red rockets and one MK5 smoke grenade."
An MK8 red rocket is a hand-held distress flare.
The firearm was reported stolen in Elsies River in 2007.
The man was expected to appear in the Cape Town Magistrate's Court on Monday on charges of possessing an unlicensed firearm and ammunition and dealing in drugs.