Rosacea is a chronic, common skin disorder whose pathogenesis is incompletely understood. An interplay of multiple factors, including genetic predisposition and environmental, neurogenic, and microbial factors, may be involved in the disease process. Rosacea subtypes, identified in the recently published standard classification system by the National Rosacea Society Expert Committee on the Classification and Staging of Rosacea, may in fact represent different disease processes, and identifying subtypes may allow investigators to pursue more precisely focused studies. New developments in molecular biology and genetics hold promise for elucidating the interplay of the multiple factors involved in the pathogenesis of rosacea, as well as providing the bases for potential new therapies.