Research in recent years at Seleukeia Sidera has revealed indications of a significant pottery production in the city during the Late Roman Imperial Period. The red slip pottery from Seleukeia Sidera seems to be similar in terms of its formal features and macroscopic characteristics of its clay fabric to that known to be produced at Sagalassos, one of the most important production centres of the region in Antiquity. Yet, as a result of detailed typological studies as well as archaeometric analysis, it has been established that a group of pottery from Seleukeia Sidera, which draws attention with its formal and decorative characteristics, is different from the Sagalassos Red Slip Ware examples. At first glance, this group of bowls, which carry a single row of pearl-like relief decoration on their everted wide rims, looks remarkably similar to the red slipped groups of the surrounding cities. However, a closer examination of the decorations and the rim form indicated distinctive differences. Similar to the examples of Seleukeia Sidera, such differences can also be observed on howls with a pearl-like relief decoration on the rim found at cities such as Arykanda, Perge and Aizanoi. Moreover, these examples are represented by only very few examples in cities other than Sagalassos. The results of the archaeometric analysis carried out on Seleukeia Sidera pottery suggest that this group was either produced at Seleukeia Sidera or in a workshop in its vicinity, as they appear more frequently there than the examples registered in the surrounding cities and have consistent subtypes as well. This production also seems to adhere to the concept of the LRD koine, put forward by Poblome and Firat. which consisted of production centres that made interrelated products resulting from sociocultural and socio-economic relations between the cities of Southwestern Anatolia during the Late Roman Imperial Period.