Cops are hunting for a pistol-packing goon over an A-train robbery spree in which he snatched cell-phones, a laptop, jewelry and a wallet from his three victims so far this month.

The crook first struck Aug. 1 at 7:25 a.m. when he walked up to a 21-year-old man on the Queens-bound train, flashed a gun and demanded his valuables.

The victim gave up his wallet and an iPhone 4, and the greedy thief then snatched a gold chain from his neck before bolting at the 80th Street station in Ozone Park.

The suspect next targeted a 27-year-old woman on a Brooklyn-bound train at 10:27 a.m. last Wednesday, asking her the time and then flashing a gun and grabbing her cellphone when she took it out to check.

He again fled at the 80th Street station.

The thug then robbed a 19-year old woman at 8:17 a.m. Sunday on a Queens-bound train after both had gotten on at Lefferts Boulevard, again asking the time and pulling a gun.

He ran at the Shepherd Avenue station after swiping her iPod and laptop, cops said.

The punk, whose image was captured on surveillance video, was described as a black male 20- to 25 years old between 5-foot-10 and 6-foot tall.