Surface acoustic waves (SAWs) have a broad spectrum of applications, especially in sensing. However, deposition methods of sensitive layers can be controlled locally through electrodeposition unlike other conventional methods, such as drop-casting and atmospheric-pressure plasma. Employing this method, we experimentally demonstrate the local electrodeposition of PEDOT: PSS on a structured active gold surface. We investigate the response of a piezoelectric transducer at 215MHz, by exploiting shear-horizontal (SH) surface waves of the ST-cut quartz substrate. The sensor responses were then tested under acetone, methanol, isopropanol and water vapor gases. Phase changes were more observed under water vapors gases. These changes depended on the surface conductivity of PEDOT: PSS deposited on the sensor. The double-port SAW gas sensors modified with the PEDOT: PSS presented the highest sensitivity in the case of water vapor, with a maximum phase shift of 0.8° and an insertion loss of about 0.5 dB at room temperature. The obtained results could pave the way to implement advanced designs of high-performance and wireless electroacoustic gas sensors based on electropolymerization.