The aim of this work is to experimentally investigate the effect of series resistance (R-s) on current-voltage (I-V) characteristics in Au/Bi4Ti3O12/SnO2 (MFM) structures. The parameter R-s, the ideality factor (n) and barrier height (square(B)) are determined by performing different plots from the experimental forward bias I-V measurements. The current-voltage characteristics of MFM structures were measured at room temperature. The values of n and square(B) were found to be 1.458 and 1.186 eV, respectively. The structure shows non-ideal I-V behaviour with ideality factor greater than unity. This behavior arises from the series resistance and the presence of an interfacial layer formed during the surface preparation. In addition, the values of R-s were determined using Cheung's method. The effect of the series resistance for the device was not ignored and the obtained values are lower than the equivalent values obtained previously without considering effect of the presence of interfacial layer. The I-V characteristics confirmed that the distribution of R-s and interfacial layer are important parameters that influence the electrical characteristics of structures.