A debris collection system for use with a portable, hand held blower/vac comprises a wheeled cart. A collection bag is releasably carried on the cart. A connecting hose releasably couples the collection bag to the fan outlet of the blower/vac to fill the collection bag with debris picked up by the blower/vac when the blower/vac operates in the vacuum mode. The cart rolls on the ground and trails behind the blower/vac in the manner of a canister vacuum cleaner as a user operates the blower/vac and walks forwardly with the blower/vac. The collection bag may be a reusable fabric bag or a disposable paper bag.