The use of herbal medicines is based on popular traditions and considered a therapeutic alternative to the use of official medicine. Incorrectly, the use of these medications is considered as exempt from adverse reactions. However, it may cause harmful effects if used with no proper guidance. After been released in the market, drugs may cause unexpected adverse reactions, making necessary pharmacovigilance work. This study aimed to investigate cases of adverse reactions registered for herbal medicines from a Brazilian pharmaceutical industry. Therefore, a descriptive, retrospective, cross-sectional and quantitative study was carried out for a period of eighteen months, through a database of spontaneous reports of unexpected events for herbal medicinnes produced by the mentioned industry. During the evaluation period, thirty-two notifications were registered, distributed among six herbal medicines containing: Trifolium pratense L, Pinus pinaster Aiton, Hedera helix L., Tribullus terrestris L., Pelargonium sidoides DC., Cimicifuga racemosa (L.) Nutt. The most reported adverse reaction, regardless of plant species, was allergy. People above fifty years old were responsible for most reports, originated mainly from Brazilian southeastern region. It was possible to conclude that most herbal medicines produced and distributed by the pharmaceutical laboratory involved in this study can be considered safe and effective for the treatment of diseases which they are designed to. In order to guarantee better contact between the notifier and the prescriber, it is important to disclose pharmacovigilance of herbal medicines among health workers. In this sense, it is possible to know the probable harmful effects, allowing actions to improve the product, ensuring its efficacy and safety.