Although gratifying progress has been made during the 20th century, much remains to be achieved. The principal objective must be prevention of HCC. Prevention of HBV-related tumors is already feasible, and prevention of HCV-related and aflatoxin-induced tumors should soon become possible. Not all HCCs are yet accounted for causatively, and the remaining risk factors need to be identified. Until primary prevention can be accomplished, attention must also be directed to obtaining a complete understanding of the pathogenesis of HCC so that strategies for secondary and tertiary prevention can be formulated and instituted. Finally, the search for effective anticancer treatment must continue.