BACKGROUND. A number of minimally invasive technologies exist for the treatment of prostate cancer (CaP), each with their associated morbidities. We sought to test the efficacy of low dose alternating electric current (LDAEC) to inhibit CaP growth in a preclinical setting and determine its effect on normal tissue. METHODS. In the first study, two power settings, 15 or 25 mA of current, and two treatment times, 15 or 60 min, were evaluated in C4-2B CaP xenografts. In the second study, power was regulated to maintain an intra-tumoral temperature of 458C in C4-2B and LuCaP 35 tumors. In both studies, tumor volume, serum PSA levels, survival and histology were analyzed. In a third study, LDAEC was applied to mice hamstrings with evaluation of gait and histology. RESULTS. The most effective tumor volume reduction in the first study was seen with tumors treated with 25 mA for 15 min (62 AE 9.4% decrease, P ¼ 0.001). Longer treatment time did not enhance treatment effect. Using 458C to govern delivery of LDAEC resulted in a near 100% reduction in tumor volume in 8/10 mice with C4-2B tumors (P < 0.001) with similar inhibition of LuCaP 35 tumors (P ¼ 0.01). This treatment, although resulting in skeletal muscle necrosis, did not affect nerves, smooth muscle and blood vessels. CONCLUSION. LDAEC demonstrates efficacy against C4-2B and LuCaP 35 CaP xenografts while causing no harm to nerves and blood vessels. These results warrant further investigations into the use of LDAEC as a treatment for CaP. Prostate