The article presents a comprehensive theory of trust in market research relationships, emphasizing the factors that influence users' trust in researchers. The theory includes individual, interpersonal, organizational, interorganizational/interdepartmental, and project factors. A sample of 779 users was tested, and results showed that interpersonal factors were the most predictive of trust. These factors included perceived researcher integrity, willingness to reduce research uncertainty, confidentiality, expertise, tactfulness, sincerity, congeniality, and timeliness. Other factors, such as the formalization of the user's organization, the culture of the researcher's department, the power of the research organization, and the extent of customization of the research, also affected trust. The findings were consistent across different types of dyadic relationships. Trust is defined as a willingness to rely on an exchange partner in whom one has confidence. It involves both belief in the partner's trustworthiness and a behavioral intention to rely on them. Trust is influenced by factors such as perceived expertise, willingness to reduce research uncertainty, sincerity, integrity, dependability, collective orientation, tactfulness, timeliness, confidentiality, and congeniality. These factors are theorized to increase users' trust in researchers. User organizational characteristics, such as perceived organizational bureaucratization, complexity, and culture, also affect trust. Clans and adhocracies are associated with higher trust, while hierarchies and markets are associated with lower trust. User organizational location and perceived power in the relationship also influence trust. Interorganizational/interdepartmental characteristics, such as perceived power and researcher culture, affect trust. Project characteristics, such as perceived importance and customization, also influence trust. The study also examined the effects of individual and organizational moderators on trust. The results showed that the relationships between trust and interpersonal characteristics were stronger for relationships involving dissimilar parties than for similar ones. The relationships between trust and organizational characteristics were stronger for interorganizational relationships than for intraorganizational ones. The study concludes that trust in market research relationships is influenced by a variety of factors, including interpersonal, organizational, and project characteristics. The findings provide a theoretical framework for understanding the factors that affect trust in market research relationships.The article presents a comprehensive theory of trust in market research relationships, emphasizing the factors that influence users' trust in researchers. The theory includes individual, interpersonal, organizational, interorganizational/interdepartmental, and project factors. A sample of 779 users was tested, and results showed that interpersonal factors were the most predictive of trust. These factors included perceived researcher integrity, willingness to reduce research uncertainty, confidentiality, expertise, tactfulness, sincerity, congeniality, and timeliness. Other factors, such as the formalization of the user's organization, the culture of the researcher's department, the power of the research organization, and the extent of customization of the research, also affected trust. The findings were consistent across different types of dyadic relationships. Trust is defined as a willingness to rely on an exchange partner in whom one has confidence. It involves both belief in the partner's trustworthiness and a behavioral intention to rely on them. Trust is influenced by factors such as perceived expertise, willingness to reduce research uncertainty, sincerity, integrity, dependability, collective orientation, tactfulness, timeliness, confidentiality, and congeniality. These factors are theorized to increase users' trust in researchers. User organizational characteristics, such as perceived organizational bureaucratization, complexity, and culture, also affect trust. Clans and adhocracies are associated with higher trust, while hierarchies and markets are associated with lower trust. User organizational location and perceived power in the relationship also influence trust. Interorganizational/interdepartmental characteristics, such as perceived power and researcher culture, affect trust. Project characteristics, such as perceived importance and customization, also influence trust. The study also examined the effects of individual and organizational moderators on trust. The results showed that the relationships between trust and interpersonal characteristics were stronger for relationships involving dissimilar parties than for similar ones. The relationships between trust and organizational characteristics were stronger for interorganizational relationships than for intraorganizational ones. The study concludes that trust in market research relationships is influenced by a variety of factors, including interpersonal, organizational, and project characteristics. The findings provide a theoretical framework for understanding the factors that affect trust in market research relationships.