Chondrocytes from epihyseal growth plate cartilage of prepubertal rabbits were cultured. Cells from the proliferative zone showed a very different adhesiveness: they did not stick to the flasks until the 8th to 10th days. They need more oxygen tension to develop and grew in small separated colonies. Each colony was composed by several layers of round or polygonal cells, metachromatic with toluidine blue and they were surrounded by one layer of fibroblastic-like cells. At the end of primary culture the colonies looked like "craters". Cells from the resting zone multiplied as monolayer culture identical to articular chondrocytes. The stage of differentiation of the two different kinds of cells is discussed.