The club thanked D'Aversa -- who replaced Claudio Ranieri last summer when the latter left for Premier League side Watford -- for the "serious and professional manner in which they conducted their work."
D'Aversa leaves after Saturday's 2-1 home defeat by Torino -- their third successive loss -- left Sampdoria just four points above the relegation zone.
They have a potentially crucial relegation six-pointer with 16th-placed Spezia this weekend but before that on Tuesday they play Juventus in the Italian Cup.
