<p>Flea parasitism can affect the fitness of the host. Whether ectoparasites and diseases play a role in the decline of the garden dormouse (<i>Eliomys quercinus</i>) was one of the questions investigated in a project on the species. We searched for fleas in garden dormouse summer nests and on 24 specimens in Germany. In 50 nests, 3,289 fleas from seven species were identified. Prevailing species in nests were <i>Ceratophyllus sciurorum</i> (1,282 / 44 nests), <i>Ceratophyllus gallinae</i> (1,973 / 23 nests) and <i>Nosopsyllus fasciatus</i>. <i>Myoxopsylla laverani</i>, was quite uncommon in nests. On the garden dormice themselves 76 (between 1 and 18 fleas) from seven species were collected and identified: <i>M. laverani</i> was the most common (38 fleas from 9 dormice), followed by <i>C. sciurorum</i> and <i>N. fasciatus</i>. It appears that the flea community of the garden dormouse in Germany is similar to what is already known from other parts of its range: predominance of the squirrel flea, abundance of bird fleas and several small mammal fleas including the northern rat flea. So far, the distribution area of <i>M. laverani</i> was thought to be limited to special thermal conditions. However, this species also occurs in the northeastern part of the garden dormouse range in Germany. Sharing some flea species with rats (<i>Rattus norvegicus</i>) and house mice (<i>Mus musculus</i>) in urban areas make garden dormice vulnerable to different infections. Consequently, ecological rat and house mouse control in urban areas should therefore be recognised as a conservation measure for the threatened garden dormouse.</p>