The effect of two microbial phytases of fungal origin (Peniophora and Consensus phytase) were evaluated for their effectiveness in improving performance and digestibility of P and Ca. A total of 44 multiparous sows were used during gestation (days 28 to 69) and lactation (days 1 to 19). Gestating and lactating sows were fed adequate P (9.9 and 27 g P per day) or low P diets (7.6 and 15.9 g per day) with or without supplementation of Peniophora (pregnancy) or Consensus phytase (lactation) providing 500, 750 and 1000 or 500 and 1000 units per kg diet, respectively. The obtained data generally indicated that graded levels of both phytases were effective in improving apparent phosphorus digestibility during gestation or lactation. The additional phosphorus release achieved when administering the recommended supply of Peniophora phytase (750 PPU/kg feed) was 0.1 g/kg feed in gestating sows, which is equivalent to 0.6 g of monocalcium-phosphate. Consensus phytase administered at the recommended dosage of 500 units per kg for lactating sows provided a release of 0.6 g P per kg feed from phytate, which corresponds to 2.5 g monocalcium-phosphate. The effectiveness of the studied phytases in pregnant or lactating sows is comparable to that in growing pigs.