James Neal scored twice and Steve Sullivan 3.
Pascal Dupuis, Matt Cooke and Paul Martin also netted goals for the Penguins, who got two assists apiece from Evgeni Malkin, Matt Niskanen, Chris Kunitz and Tyler Kennedy.
Marc Andre-Fleury made 24 saves in the win.
David Ullstrom, Milan Jurcina and Kyle Okposo tallied for the Islanders, who have dropped two straight.
Al Montoya stopped just 25-of-31 shots in the loss.