Background Drug promoting brochures can influence physicians prescription patterns. The validity of the info presented in these brochures is of major importance. World Health Organization (WHO) issued criteria to guarantee validity, equity and ethical presentation of data in medical brochures. This study aims to evaluate the quality and the validity of information presented in the pharmaceutical brochures distributed among family physicians in Lebanon. Methods Pharmaceutical brochures were randomly collected at the family medicine center in Hôtel Dieu de France hospital in Beirut - Lebanon. These brochures were evaluated in reference to the WHO ethical criteria for medicinal drug promotion and on guidelines for quality assurance of the graphs, references, texts and illustrations. Results Among the 60 brochures collected, only 4 fulfilled all the WHO ethical criteria, and 24 presented less than half the required criteria. Information concerning the drug safety are the least mentioned. Only 11.8% of the presented graphs are based on studies of high methodological level. Half of the brochures presented necessary information to identify studies references which are not always retrievable. Texts present mainly brand names instead of generic names and emphasize on information reflecting the drug efficacy. Conclusion The pharmaceutical brochures in this study presented incomplete or invalid information. Prescribing physicians should be aware of the claims found in the brochures distributed by pharmaceutical companies and should be familiar with the principles of the evidence-based medicine to be able to critically appraise the validity of the reference studies and avoid the pitfalls in graphs reading.