Although numerous studies have examined factors influencing engagement in political consumerism, scholars have paid less attention to the role of consumer beliefs. The present study aims at conceptualizing the role of perceived consumer effectiveness (PCE) as both an antecedent of political consumerism and a condition that can strengthen the impact of other attitudinal factors on political consumerism. The study also examines the relevance of consumer cynicism as a predictor of political consumerism. Analysis of a representative survey in Hong Kong (N = 1003) shows that PCE indeed relates to engagement in both boycotting and buycotting. Consumer cynicism, meanwhile, explains engagement in boycotting only. In addition, PCE serves as a contributory condition that strengthens the impact of consumer cynicism on boycotting as well as the impact of the pro-democracy stance on buycotting. The study highlights the relevance of consumer beliefs to engagement in political consumerism.