The growth and morphology as well as collagen biosynthesis of human fibroblasts obtained and cultured on sepiolite-collagen complexes have been studied. No differences on cell morphology and growth properties nor collagen synthesis were observed when compared with standard culture substrates. The type I/type III ratio of biosynthesized collagen by fibroblasts cultured on sepiolite-collagen complexes was about 5-6 with no difference when compared to control conditions. This normal behavior was also observed for the type I/type III procollagens. According to these studies the sepiolite-collagen complexes do not modify the studied features of the fibroblasts.