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Altative refrigerant R-134a is considered to be ozone-friendly and a potential candidate for replacing the refrigerant R-12 in refrigeration and air-conditioning applications. This paper presents an experimental investigation on condensation heat transfer of the altative refrigerant R134a flowing inside a helicoidal pipe with the cooling water flowing through the annular helicoidal passage in a counterflow direction. The heat transfer experiments were performed for R-134a mass flow flux ranging from 100 to 420 kg/m2 s with the superheat of the inlet vapor of 2. 8℃ and 8. 3℃, respectively. The average Nusselt numbers were experimentally determined for a helicoidal pipe with the helix axis of vertical direction. In addition, the obtained experimental results were compared with the results for R-134a condensation in straight and helicoidal pipes available in the open literature.