Beef longissimus thoracis et lumborum (LTL) muscle was used to evaluate the effect of PEF treatments (1.4 kV/cm, 10 Hz, 20 μs, 300 and 600 pulses) on meat quality attributes (weight loss, colour, cook loss and texture) and its evolution at various stages during ageing (2, 10, 18 and 26 days post-mortem). The length of meat ageing before and after PEF application exerted no influence on weight loss, colour and cook loss. Results also demonstrated that PEF treatments applied at different times post-mortem (2, 10, 18 and 26 days) showed a tendency towards reducing toughness of beef samples but that the application of PEF did not affect the tenderization process provided by ageing itself. 60% of the sensory panellists scored PEF treated samples as tender (≥6.0 points out of 9.0) whereas only 27.5% did so for untreated samples.