AbstractAlthough control strategies are widely used to mitigate opportunistic behaviors, their implementation in consulting projects with intangible outputs can be challenging. Whether or not control strategies are effective to curb consultants’ opportunistic behaviors remains unknown. To fill the knowledge gap, this study examines the effects of clients’ control strategies on consultants’ opportunistic behaviors in consulting projects, with requirement risks and information asymmetry as moderators. The results from a questionnaire survey of 360 architectural and engineering design consultants showed that outcome control breeds opportunistic behaviors. This effect is exacerbated in projects with high levels of requirement risks or information asymmetry. It was also found that behavior control constrains opportunistic behaviors. The findings complement the project management literature by providing empirical evidence for the role of control strategies in curtailing design consultants’ opportunistic behaviors and by revealing that the tangibility of project outputs is an important contextual factor for mitigating opportunistic behaviors.