Samp had not won since October 26 and their record of just two points from five games had seen them sit precariously close to the relegation zone.
For Catania it was their third successive defeat and keeps them rooted firmly to the bottom of the table.
It was all Sampdoria in the first half with Gabbiadini heavily involved, his right-footed shot saved by Alberto Frison before firing narrowly wide moments later.
Nicola Pozzi was played in by Andre Coasta but his shot from the edge of the area went over the bar.
Eder then had a chance but Frison comfortably saved before Costa and Roberto Soriano both fired over from distance as half-time arrived with the game goalless.
The hosts began the second half in much the same manner they ended the first, Pedro Obiang firing wide.
However, it had only been a matter of time before Catania were breached and that came about nine minutes into the second half.
Lorenzo De Silvestri sent a right-wing cross into the box which found Eder at the far post and he slotted home from close range.
Obiang fired high and wide before Eder attempted to chip Frison at the far post but the goalkeeper managed to block.
Sampdoria then sealed victory with a second goal 13 minutes from time with a classy finish by Gabbiadini, curling home at the far post with the keeper well beaten.
Gabbiadini came close to adding a third a minute from time but Frison managed to go down to his left to thwart his shot from outside the box.