A human osteosarcoma derived cell line was treated with phorbol-12-myristate-13-acetate and was subsequently cloned extensively. 27 clones were examined for their initial rate of aggregation, their attachment to homo- and heterotypic performed cell layers, and the size of their 24-hour aggregates. Quantitative differences for these three adhesive parameters were observed between the clones. Based on these findings five clones were studied in more detail. The adhesive differences between these clones were stable, reproducible, and dependent on the assay system. This human clonal system will be a valuable tool to study the molecular nature of the adhesive properties of these cells.