Biphasic calcium phosphate (BCP) bioceramics, for use as resorbable bone substitutes, containing both isolated macropores and interconnected micropores, have been fabricated by sintering, using naphtalen particles as a porogen to produce macropores. The resulting ceramics contain ~ 45% macropores and various amounts of microporosity. Mechanical properties (compression and bending strength, toughness and hardness) have been measured and modeled by combining two approaches, at two different scales: the one describes the mechanical properties of a partly sintered stacking of grains, supposed to account for the interconnected microporosity, the other one holds in the case of closed and isolated macropores within a continuous matrix. The material is then represented as a quasi-continuous matrix containing macropores, the matrix being itself microporous. The model also considers that fracture always initiates on a macropore, which allows to set a correspondence between fracture toughness and fracture stress equations. The mechanical tests performed on the sintered ceramics tend to validate the modeling approach.