Phytases may ameliorate phytic-P antinutritional properties. The aim of the present work was to evaluate comparatively the effects of Aspergillus fumigatus (AFP) and A. niger (ANP) phytases included in a growing pig phytate rich diet (rape seed, maize and barley) at the level of 500 U/kg. The phytic-P rich diet systematically induced hypophosphataemia, hypercalcaemia and hyperphosphatasaemia. Mean phosphataemia was increased and mean phosphatasaemia and calcaemia were decreased by the ingestion of AFP or ANP. The apparent digestibility of P was significantly higher for the AFP diet (52.8%) than for the ANP diet (46.5 %) or the control diet (30.8%). The improvement in Ca digestibility by AFP and ANP was not statistically significant. AFP and ANP significantly decreased the P concentration in faeces by 33 and 17%, respectively.