In a study of book reviews published in four general medical journals over a six-month period, 480 reviews were analyzed. Twenty-five features that reviewers address when evaluating a text were identified, and the frequency of commentary for each feature was determined. The mean number of features addressed per review was 9.0. Reviews averaged 389 words, but review length did not correlate with the length or scope of the book, with the number of features addressed, nor with the reviewer's assessment of the text. Extraneous commentary by the reviewer occurred in 16% of the reviews. This editorializing appeared in lengthier reviews that addressed fewer features. Favorable reviews were far more common than unfavorable ones (88.5% vs. 11.5%). Consequently, for the fifty-five books reviewed in more than one journal, agreement regarding rating of the text was high (86%). Results of this study may provide useful guidelines for reviewers of medical texts.