OBJECTIVES: To evaluate whether the quality of pharmaceutical company representatives' (PCRs) visits to hospital pharmacists can be improved by written communication of the results of an evaluation of their visits. METHODS: Pilot study with prospective evaluation of overall visit quality and strength of request for adding drugs to the hospital formulary, and of the scientific quality of products presentations using a standardized form. Two one-year study periods (59 vs. 61 visits) separated by the intervention (global results of the first period sent to each drug company). RESULTS: No difference was observed between both periods in overall visit quality (VAS 0 = null, 10 = excellent: mean 4.7 (2.1 SD) vs. 5.2 (2.1) or strength of request for adding drug to hospital formulary (VAS 0 = null, 10 = extreme: 7.0 [2.6] vs. 7.2 [2.7]). Clarity and scientific value of products' presentations and scientific value of responses were better during the second study period, as a sign of quality improvement. CONCLUSIONS: This study suggests that systematic quality evaluation of PCRs visits and communication of results to drug companies may improve the scientific quality of products' presentation.