In this study, nanostructured polypyrrole (PPy)-coated cotton textiles were produced by in situ chemical oxidative polymerization and dielectric/electrical properties of PPy-coated cotton fabrics were presented in the low-and highfrequency regions. The conductive cotton fabrics showed a relatively high dielectric constant in the low-and radiofrequency region. The dielectric constant and dielectric loss for all fabrics presented relatively high values at low frequency and were found to decrease with the frequency. The influence of the PPy content and the type of dopant and oxidant on the morphological, dielectric/electrical and thermal properties of the cotton fabrics was investigated. It was found that the type of dopants and oxidants had a noticeable effect on the electrical/dielectric and morphological properties. The frequency dependence of AC conductivity, dielectric constant, dielectric loss and electric modulus were analyzed in the frequency range from 0.1 kHz to 10 MHz. The nanofiber network morphology of coated fabrics produced by dodecylbenzenesulfonic acid sodium salt improved the electrical/dielectric and thermal properties of cotton composites.