AbstractHL‐60 cells, growing as single cells in suspension, exhibit marked cell‐cell adhesion when treated for 24 hours with 10μg/ml RRR‐α‐tocopheryl succinate, also called vitamin E succinate (VES). VES‐induced cell‐cell adhesion is dependent on divalent cations and a functional cytoskeleton and is protein mediated. Cell adhesion molecules CD11a/CD18, CD11b/CD18, CD29, and CD54 do not appear to be mediating VES‐induced cell adhesion. HL‐60 cells treated with VES adhere to fibronectin‐coated plastic and secrete elevated levels of fibronectin. A 72‐kDa fibronectin‐binding membrane molecule was detected on VES‐treated HL‐60 cells, and antibodies to fibronectin were shown to inhibit VES‐induced cell aggregation. VES induction of HL‐60 cell‐cell adhesion is proposed to result from increased amounts of extracellular fibronectin binding to VES‐induced cell surface fibronectin‐binding molecules.