This article will first review the advantages of acrylic / polyurethane hybrid waterborne sealant formulations, and the routes to producing a polyurethane / acrylic base polymer system. The article will then describe possible starting formulations and appropriate market segments where these sealants are projected to compete. Hybrids consisting of acrylic and polyurethane polymers have become a relatively important class of materials in the paint and coating industry. These materials take advantage of cost reduction afforded by the acrylic portion and the advantageous performance properties of the polyurethane portion of the formulation. Similar hybrids are now being introduced as sealant formulations for the same value propositions. There are several commercial acrylic / polyurethane sealants available today, and additional formulation development promises to make strong statements in the construction and do-it-yourself market segments. These products possess excellent adhesion to many surfaces.