The effect of intermolecular interaction of Phthalic acid (PA) and nonionic surfactants on electrodeposition was studied and the electrodeposition of tin was used as a model system. The CV curve of the electrolyte in the presence of a combination of PA and Triton X-100 (TX100) indicates that a relatively compact adlayer forms on the electrode surface and the electrodeposition of tin is inhibited very well. It is expected that the aromatic character of the hydrophobic moiety of both TX100 and PA enhance the binding interaction and the blocking effect is governed by the intermolecular interaction between PA and TX100. Scanning electron microscopic (SEM) image shows that a smooth, regular and compact deposit was obtained from the electrolyte with both PA and TX100. A relatively low carbon content of the deposit indicates that the incorporation of the additive in a deposit is strongly controlled in the presence of both PA and TX100. The possible explanation for the reduced incorporation may be proposed as the formation of the linkage of the molecules caused by intermolecular interaction between PA and TX100. (C) 2014 The Electrochemical Society. All rights reserved.