Gastroparesis is a chronic disease of stomach mobility, defined as delay in the emptying of food from the stomach without mechanical obstruction. Various methods are used for the diagnosis of gastroparesis and scintigraphy method is accepted as the gold standard. In this study, Electrogastrogram (EGG) signals were obtained from gastroparesis patients and healthy volunteers using cutaneous electrodes. Unlike the methods used in the frequency analysis of EGG signals in the literature, parametric methods have been used in this study and the selection of the method to be used has not been determined intuitively, it has been determined by mathematical calculations. Cramer-Rao Lower Bound (CRLB) method has been used to determine which method should be used for obtaining Power Spectral Density (PSD). Using selected parameter estimation method, PSD functions were obtained. Several features were extracted from the PSD functions and they were utilized to differentiate patient and healthy groups. As a result, features that can classify EGG signals from gastroparesis patients and healthy subjects, have been obtained. Best electrode placement that can be used for this disease has been achieved succesfully.