Attracted by business opportunities, particularly in trade, people of Dubrovnik go to Bosnia and in the significant mining and commercial areas form their colonies where they live longer or shorter period of time. In some of those colonies people of Dubrovnik started to appear in the second half of the 14th century, while they experienced full intensity in the first half of the 15th century. It is significant that in some colonies few people of Dubrovnik occurred at the same time. Srebrenica and Zvornik and other Dubrovnik colonies were inhabited by nobles and commoners originating from Dubrovnik where landowners were regularly elected in the judicial commission as a consuls or judges. There were also a certain number of commoners who became rich and thus become an important factor that was involved in the economic and political spheres of life, and some of them had also been elected to the judicial commission. Many were involved in the credit-trading activities. Mining contributed to strengthening of foreign trade particularly silver and lead by which the Bosnian mines were known for. Increased involvement of the people of Dubrovnik in mining was associated with the fall in production of silver and its demand at the European market. Along with the development of trade, crafts developed as well, in which the people of Dubrovnik mediated in involvement of locals. Trade exchange has brought Western influences that were manifested in many aspects of life. The daily life of the people of Dubrovnik in Srebrenica, Zvornik and their other colonies in Bosnia was conducted in a similar way as the one in Dubrovnik. The people of Dubrovnik brought the qualities of Dubrovnik, and with it they have brought the features of European culture. Dubrovnik's influence found its footing in the religious aspect, especially because the people of Dubrovnik were Catholics. Many of them profusely donated the church and the Franciscans as evidenced by their testament. Their high fluctuation resulted in various disputes that were under the jurisdiction of Dubrovnik and mixed courts. Based on unpublished sources of the state archives in Dubrovnik, published sources and literature, this research paper will present how the people of Dubrovnik affected the life of the observed colonies.