The analysis of Ordovician trilobite faunas of Saxothuringia and their comparison with contemporaneous trilobite faunas of Perunica are presented. However, the new analyses of data on Ordovician trilobites do not definitely solve the question whether an ocean was developed between these two regions. Indirect clues based on the occurrences of similar trilobite faunas in the two regions are too much ambiguous. During the Tremadocian, a connection between these two terranes cannot be ruled out as suggested by shared trilobite taxa. Such observations are, however, mostly confined to the Allochthonous Units in Bavaria. During the Dapingian to Darriwilian, faunal exchanges between Saxothuringia and Perunica probably existed as suggested by similarities of the trilobite assemblages of the Griffelschiefer Formation in the Schwarzburg Anticline and the upper Klabava and Šárka formations in the Prague Basin. Relations to Iberia (e.g. Valongo Formation, Anticlinal de Valongo) should be also taken into account. These similarities include a common occurrence of the same genera, possibly even species, in all these areas. Important differences, however, exist such as the absence of several trilobite groups in the Griffelschiefer Formation, which are common in Perunica and Iberia. These similarities and differences can be explained by palaeogeographical proximity/distance, different ages of these formations, but also by facies (depth/substrate) dependence of diverse trilobite groups. The low-diversified trilobite assemblage of the Kalkbank (Schmiedefeld Formation, late Katian, Schwarzburg Anticline) shows several elements shared with contemporaneous trilobite assemblages of Perunica, but also endemic, conservative taxa. The majority of taxa existing in the Saxothuringian and shared with Perunica were (possibly) good swimmers, which were able to span large distances. Specific trilobite faunas of the Lederschiefer are endemic and differ considerably from the contemporaneous trilobite faunas of Perunica. Lederschiefer taxa are, however, confined exclusively to the dropstone pebbles drifted by ice, and their palaeogeographical significance is thus low. We suppose that observed differences in trilobite faunas were not caused by presence of a wide ocean but should rather be ascribed to local environmental/substrate conditions.