The higher the severity of HIPEF-processing parameters, the lower the retention of vitamin C in watermelon juice. On the other hand, the maximum values of lycopene and antioxidant capacity were obtaining at high electric field strengths (25 and 35 kV/cm) and frequencies around 200 Hz, applying bipolar 4–7 ls pulses. As watermelon juice has been shown to be an excellent source of lycopene and antioxidant capacity is highly related to its content, both parameters could be used during storage to assure a juice with high antioxidant potential.