This study explored one of the less studied types of conspiracy theories, namely those concerned with business, organisations and industry. In all, 400 participants completed a 60-item questionnaire which covered a number of areas such as dishonest advertising, bribery and corruption. Given the opportunity to respond “don’t know”, a large number (>25%) responded that way to very specific questions. Overall, it seemed that consumers believed drug, oil and tobacco companies were dishonest and devious in their marketing. Also, they believed many manufacturers and advertisers attempted to manipulate and trick customers. Four factors resulted from a number of analyses though correlations and regressions suggested that demographic (age, sex, class) and ideological factors (religious and political beliefs) were not strongly related to business conspiracy theories suggesting consensus. Implications for understanding how conspiracy beliefs relate to product purchase and consumer boycotts are discussed.