Given the visibility and accessibility of human skin to investigators interested in inflammatory and immunologically-mediated disorders, it should not be too surprising that dermatological disease-related studies are continually being reported in the worldwide literature. As such, it is difficult to keep pace with developments regarding the pathophysiology and treatment of various skin disorders. Even though many advances have been made regarding; identification of a new virus that may cause skin lesions (i.e. HHV-8) (Chang et al., 1994), characterization of proteins that inhibit bacterial invasion of the skin (Frohm et al., 1997), and gene mutations responsible for causing cutaneous neoplasms such as basal cell carcinoma (Xie et al., 1998; Dahmane et al., 1997; Oro et al., 1997; Fan et al, 1997), this chapter will be devoted exclusively to the molecular and cellular basis for leukocyte (i.e. neutrophil) and immunocyte (i.e. T-cell) adhesion in the skin. Indeed, the past decade has been characterized by rapid progress in elucidating key adhesion molecules, cytokines, and chemotactic polypeptides which govern the nonrandom trafficking of circulating cells into the dermis and epidermis.