Cell culture models are becoming prevalent in the investigation of tissue responses to implant materials. Cellular attachment and cell adhesion studies can aid in the development of more effective orthopaedic and dental implants. Cell attachment was studied on extracellular matrix proteins (type I, IV collagen, peptide solubilized elastin (PSE), fibronectin laminin). Human osteoprogenitor cells responded differently to these collagenous and non-collagenous proteins. PSE and type I or type IV collagen are the most effective proteins in cellular attachment and cell spreading. Cell behaviour was measured in the presence of macroporous materials (Porites astreoi'des from the West Indies and a bovine hydroxyapatite ceramic ENDOBON '~) and bioartificial connective matrices comprising hydroxyapatite, peptide solubilized elastin, collagen, fibronectin and chondroftin-6-sulfate, components of the extracellular matrix (ECM). Human osteoprogenitor cells responded differently to the materials tested according to the content of components of ECM. About 40% of attached cells were obtained on the composite materials PSE, collagen, fibronectin and chondroTtin-6-sulfate, and about 10% on the macroporous materials, whatever their porosity and their chemical components. These results demonstrate a need for more effective surface treatment to promote cell attachment, cell spreading and cell growth.