Unconscious bias may interfere with the interpretation of research from some settings, particularly from lower-income countries. Most studies of this phenomenon have relied on indirect outcomes such as article citation counts and publication rates; few have addressed or proven the effect of unconscious bias in evidence interpretation. In this randomized, blinded crossover experiment in a sample of 347 English clinicians, we demonstrate that changing the source of a research abstract from a low- to a high-income country significantly improves how it is viewed, all else being equal. Using fixed-effects models, we measured differences in ratings for strength of evidence, relevance, and likelihood of referral to a peer. Having a high-income-country source had a significant overall impact on respondents' ratings of relevance and recommendation to a peer. Unconscious bias can have far-reaching implications for the diffusion of knowledge and innovations from low-income countries.