AIM: The aims of this study were: a) to verify if the instructions displayed on the packages and labels of dental plaster available for purchase in the city of Porto Alegre are in accordance with the Brazilian laws, and b) to analyze how information is available on packages and labels of dental plaster acquired by dentists. METHODS: For this study, it was used the method proposed by Silva et al. (2010) modified, according to which the information related to instructions for product use displayed on packages and labels, if present, provided by manufacturers and/or importers from each brand of plaster was reviewed: how to use, composition, price, expiration date, health risks and disposal instructions. The collected information was subsequently confronted with the requirements laid out in national legislation on trade of dental plaster. RESULTS: No product showed the price or the instructions for disposal. One brand showed no information of the package and another one showed only the composition of the product; this requirement was present in most products. The mode of use and the expiration date were present in almost all packages, except for two brands. Only two brands presented information on health risks, and yet unsatisfactory. CONCLUSIONS: The different brands and types of dental plaster analyzed presented some kind of violation of the provisions of the Brazilian legislation, most with missing or unsatisfactory information.