Many people deserve recognition for helping me present the narrative semiotic method used in this study. The credit for achieving the present level of clarity is largely theirs: Stephen Barley, Janice Beyer, Janet Dukerich, Roger Dunbar, Jane Dutton, William Guth, James Hoover, Anne Huff, Marjorie Lyles, Frances Milliken, Linda Pike, and the editor and anonymous reviewers of Administrative Science Quarterly. This research was partially supported by a grant from the Tenneco Fund. In an attempt to explain differences in the propensity of organizations to enter into joint ventures, this study uses a semiotic method of textual analysis to examine CEOs' letters to shareholders as they reflect the existence and strength of boundaries separating internal organizational subunits and boundaries separating the company from external environments. These boundaries are linked to the propensity of ten companies in the chemical industry to engage in joint-venture activity. Weak internal or interdivisional boundaries and strong boundaries separating the company from the external environment were prevalent in firms having no joint ventures; strong interdivisional boundaries and weak external boundaries were prevalent in firms having several joint ventures.