Arrington ran for a 4-yard touchdown in the first quarter and caught a 6-yard scoring pass from Kurt Warner in the third.
Warner passed for 395 yards in the third straight win for the Cardinals (7-3), who survived a fourth-quarter Seattle rally to get the win.
Anquan Boldin hauled in 13 Warner passes for 186 yards and Larry Fitzgerald caught 10 for 151 yards.
Rackers' field goals were from 38, 48, 54 and 26 yards.
Matt Hasselbeck passed for 170 yards and a touchdown, with three interceptions, for Seattle (2-8).
T.J. Duckett ran for 1- and 2-yard touchdowns for the Seahawks, both in the fourth quarter.