The effect of the addition of pectin on the rheological properties of thick yogurt was studied with the purpose of establishing the optimal dose. Samples were prepared with pectin concentrations of 0.05, 0.10, 0.15, 0.20, 0.25 and 0.30% w/w. The main physical and chemical properties were evaluated. Sineresis was analyzed by centrifugation measuring the separation of liquid from the milk gel, firmness was determined using a Forney penetrometer and viscosity by the use of a Brookfield viscosimeter. The sensory properties were also evaluated. The best results were obtained in yogurts with additions of 0.15% of pectin.