Primary chondrocyte culture was carried out after enzymatic digestion of femoral and tibial epiphyseal cartilage of human fetuses, collected with informed parental consent within 12 h postmortem. Chondrocytes were cultured in HAM F-12 medium with penicillin and 15% serum. Three types of serum were used: human placental cord serum (HPS), fetal calf serum, and human male adult serum. Chondrocytes cultured with HPS grew as monolayers, formed abundant colony groups with a highly metachromatic pericellular matrix, and floating round cells were observed in the culture medium. By the 10th day of culture the great majority of proteoglycans present in the culture medium were found as aggregates. Chondrocytes cultured with fetal calf serum or human male adult serum grew as monolayers, were polygonal in shape, and the pericellular matrix was far less developed than in HPS cultures. By the confluent phase of growth, only approximately a third of the proteoglycans present in the culture medium were found as aggregates. Chondrocytes cultured with HPS proliferated significantly more rapidly than those cultured with fetal calf serum or human male adult serum. The results suggest that certain, as yet unidentified, factors are present in sufficient amount in HPS to allow chondrocytes in culture to retain phenotypic morphological and biochemical characteristics. HPS also facilitates growth of human fetal epiphyseal chondrocytes in culture. Primary human fetal epiphyseal chondrocyte culture could be a suitable experimental tool for the in vitro study of biochemical characteristics of cartilage and factors involved in fetal cartilage metabolism. © 1985 International Pediatric Research Foundation, Inc.