Ferromagnetic manganite films (La0.7Sr0.3MnO3 (LSMO) and La0.7Ca0.3MnO3 (LCMO)) have been deposited on lattice-mismatched perovskite single-crystalline substrates. Strained epitaxial growth is obtained using the pulsed laser deposition (PLD) technique, A pseudomorphic growth is observed up to a critical relaxation thickness, the value of which depends on the lattice mismatch. Above this critical thickness, the films do not relax homogeneously, Characterisation of the fully strained films has been carried out and the modifications of their magnetic and transport properties are discussed in relation with changes in the MnO6 octahedra geometry. (C) 2002 Elsevier Science B.V. All rights reserved.