Celebrity endorsement is prominent in advertising today. Increasingly, marketers are using multiple celebrities to endorse a product in an advertisement. Despite extensive research on celebrity endorsement, extant literature provides little insight regarding the effectiveness of multiple celebrity endorsement. The present research contributes to the marketing literature by filling this important gap. Specifically, it examines the relationships between multiple celebrity endorsement and the consumer's attitude toward the advertisement, attitude toward the brand, and purchase intention. It examines these relationships for two product categories, characterised by low and high consumer involvement. The direct impact of the type of product category included in the advertisement on consumer evaluations of the advertisement is also examined. Two studies were conducted to examine the effectiveness of multiple celebrity endorsement. An experimental design was included in the survey instrument used to collect data from a mall intercept survey of consumers at an Australian state capital city. The proposed framework was tested for two product categories: snack bars and televisions. Multivariate analysis of variance of the data revealed that consumer evaluations of an advertisement were not influenced by the number of celebrities portrayed in the advertisement. The impact of multiple celebrity endorsement on consumer advertisement evaluations did not vary by product category. However, consumer evaluations of an advertisement varied according to the product category. The findings point to a number of important theoretical and managerial implications.