Entomological postage stamps are unique means of communication of science with the public and have been suggested as effective teaching tools in primary and secondary education. A survey of the taxonomic and other information contained on insect- and arachnid-themed stamps issued globally from 1891 to 2020 reveals that 30% of these stamps contain various errors and are scientifically unreliable. In addition, representations of insects are highly biased towards only two orders (Lepidoptera and Odonata), while other mega-diverse orders (e.g. Coleoptera, Diptera, Hymenoptera) are poorly represented or not represented at all. This phenomenon can negatively affect public perception of priorities in biodiversity and conservation. Standardization of taxonomic information on entomological stamps and implementation of rigorous quality control measures are encouraged to assure dissemination of accurate scientific information.