We report surfactant-induced instabilities along the wetting meniscus of an oil-water-solid system which are discussed through density fluctuations of the interfacial molecular film, coupled with variations of the meniscus shape according to Laplace＇s relation gamma J similar to(Delta rho g)z, where J=(1/R-1+1/R-2). The results show that two critical parameters exist which govern these instabilities and can be tuned to either magnify or suppress them. These are (i) the initial flux close to the meniscus and, (ii) the size and structure of the amphiphiles. The first parameter determines through the interfacial adsorption amount (partial derivative Gamma/partial derivative t) both the magnitude and rate of the meniscus reconformation similar to partial derivative(gamma J)/partial derivative t. The higher partial derivative(gamma J)/partial derivative t, the higher the inertia of the moving meniscus fluid (rho upsilon(2)/2) and the more the interfacial film is compressed beyond its equilibrium position and enters the unstable regime. The molecular size and structure are found to determine the stability and response of the film to the oscillations of the meniscus. A description of these instabilities, their concentration-profile- and molecular-size-dependent behaviors is then proposed.