Objective: To compare different wording approaches for conveying the strength of health care recommendations. Study Design and Setting: Participants were medical residents in Canada and the United States. We randomized them to one of three wording approaches, each expressing two strengths of recommendation, strong and weak: (1) "we recommend," "we suggest;" (2) "clinicians should," "clinicians might;" (3) "we recommend," "we conditionally recommend." Each participant received one strong and one weak recommendation. For each recommendation, they chose a hypothetical course of action; we judged whether their choice was appropriate for the strength of the recommendation. Results: The response rate was 77% (341/441). Most participants, in response to strong recommendations, chose hypothetical courses of action appropriate for weak recommendations. None of the wording approaches was clearly superior in conveying the strength of a recommendation. However, different approaches appeared superior depending on the strength and direction (for or against an intervention) of the recommendation. Conclusion: No wording approach was clearly superior in conveying the strength of recommendation. Guideline developers need to make the connection between the wording and their intended strength explicit. © 2012 Elsevier Inc. All rights reserved.