PurposeOnline reviews shape consumer decisions, even in healthcare, a credence service where expertise is difficult to evaluate. Like unethical retailers, some healthcare providers post fake reviews. However, the impact of fake reviews on potential patients remains unclear. Using a dataset of fake reviews, this study examines how patients perceive the helpfulness and trustworthiness of fraudulent vs genuine physician reviews.Design/methodology/approachWe used an archival dataset containing a representative sample of 5,000 online physician reviews, both fake and genuine, and performed empirical analysis. In addition to the helpful votes obtained from the data, we used large language models to derive the perceived trustworthiness score.FindingsFake physician reviews are paradoxically perceived as more helpful and trustworthy than genuine reviews. To unravel the underlying mechanism, we investigated the extent of personalized and specific health information. We found that fake reviews often contain more personalized and specific health information, making them appear more credible.Research limitations/implicationsResults may not generalize beyond online physician reviews. Future research could extend this investigation to other contexts.Practical implicationsOnline platforms may need to reconsider their approach to managing online reviews, address ethical concerns, and strengthen regulatory oversight in sensitive areas, particularly in healthcare.Originality/valueThis study highlights an ethical paradox: while patients seek detailed health information, privacy concerns limit real patients from sharing such details, creating an information gap that fake reviews exploit. This is the first study to make use of unique data that contains real fake online physician reviews.