This study compared the effect of a surfactant on surface detail reproduction between combinations of addition-cured silicone impression materials and type IV stones. Six hundred impressions were made of a ruled test block using; Examix-NDS, Doric-Es Flo-Light, Panasil Contact Plus, Extrude Wash and President Plus Jet. Half of the impressions were treated with a surfactant (Aurofilm). Impressions were poured with type IV dental stones; Silky Rock, Fuji Rock, Suprastone and Vel-Mix and the 20 mu line was scored. A laboratory surfactant (Aurofilm) significantly reduced (P<0.01) compatibility with; (i) Examix-NDS and Suprastone, (ii) Examix-NDS and Velmix, (iii) Extrude Wash and Fuji Rock.