High-frequency, low-intensity electric fields generated by insulated electrodes have previously been shown to inhibit bacterial growth in vitro. In the present study, we tested the effect of these antimicrobial fields (AMFields) on the development of lung infection caused by Pseudomonas aeruginosa in mice. We demonstrate that AMFields (10 MHz) significantly inhibit bacterial growth in vivo, both as a stand-alone treatment and in combination with ceftazidime. In addition, we show that peripheral (skin) heating of about 2 degrees C can contribute to bacterial growth inhibition in the lungs of mice. We suggest that the combination of alternating electric fields, together with the heat produced during their application, may serve as a novel antibacterial treatment modality.