This article explores the effects of party organizational strength on party success and survival in the new postcommunist democracies. Organizational strength is defined as extensive network of branch offices, large membership, and professional staff. Using quantitative information on parties in the Czech Republic, Estonia, Hungary, and Poland, the study shows that strong organization helps parties increase their vote share significantly and steadily. Focused comparisons of “most similar” parties with different electoral performance from Estonia and the Czech Republic further exemplify the significant independent role that organizational strength plays in helping parties succeed electorally.