Evidence-based medicine (EBM) relies on accurate data derived from well-designed, clinically relevant randomized controlled trials (RCTs). Most randomized trials, however, are conducted by industry sponsors aiming at licensing and marketing drugs, which may weaken the usefulness of the findings to EBM. Disturbing evidence has emerged of widespread biases in industry-sponsored trials, including publication bias, selective reporting of findings, and distorted interpretation of results. These practices compromise the professional integrity of physician-investigators who contribute to them. In turn, the well-being of patients participating in RCTs may be jeopardized, and the evidence base upon which EBM is practiced may be corrupted. Regulatory reform alone will be inadequate to resolve these problems; attention must also be paid to physicians' professionalism. The authors recommend a change in the culture of academic medicine whereby physician-investigators who maintain professional integrity are rewarded or recognized. Educational interventions promoting integrity in clinical research may be one part of affecting such change.