Colloids like milk, paints, inks, ice cream among others, are substances presented in the everyday life. The colloidal stability is a determining feature of their quality and this feature is quantified through the zeta potential, which is conventionally measured with expensive and non-portable equipments. In this work it is presented the use of Digital In-line Holographic Microscopy (DIHM) to measure the zeta potential of colloidal systems. The achieved results agree with those obtained with a commercial instrument, which added to the proved portability of DIHM make this alternative method a very attractive option for in-situ studies of colloidal stability.