High energy shock wave lithotripsy has proven to be an effective tool in the management of renal calculi. The effects of electrohydraulically generated high energy shock waves (HESW) on tumor cells were described only recently. Here we present data on the experimental design for treatment of tumor cells, using electromagnetically generated shock waves. The determination of the focal area, in which pressures are at least 50% of the maximum pressure, appeared to be essential. In vitro HESW treatment resulted in a dose dependant anti-proliferative effect on Dunning R-3327 PAT-2 rat prostate cancer subline, determined by temporal growth curve analysis after plating of treated cells in soft agar. Furthermore, it was shown that HESW treatment had a potentiating effect on Vinblastin treatment. The combination of HESW with Vinblastin appeared to have an additive in vitro anti-proliferative effect on PAT-2 prostatic cancer cells.