This master thesis deals with illegitimate births, which are not analyzed enough in Croatia. Peninsula Pelješac was inhabited in ancient times. Over the years, while it was a part of Republic of Ragusa, it developed a lot more than the other parts of Dalmatia. Because of that a lot of people migrated to the peninsula, but today depopulation is increasing. The inhabitants were under the influence of social and economic factors which were also under the influence of geographical position. The geographical position did spare the peninsula from many wars and battles but at the same time it did not help with the social and economic development of the peninsula. Pelješac is known for vineyards and other agricultural crops, tourism and seafaring. All of these are still present today, but tourism dominates. In the past, society looked differently at illegitimate children. Their mothers would abandon them after their birth and they were often bullied by society. One aspect was legalized after some time because of their parents wedding ceremony. Over the years, people changed and accepted them. Today is a lot easier to be an illegitimate child, especially in more developed countries where are the highest rates of illegitimate births. In Croatia the number of illegitimate births increased in the last 20 years. County that has the highest percentage of illegitimate births is Međimurje County, and the one with the lowest percentage is Split-Dalmatia County. Because of the small number of inhabitants on the peninsula, there are not many births nor illegitimate births. Cities that were analyzed showed a low number in illegitimate birth rate and for many years of the analyzed period there were not illegitimate births. Of all th analyzed cities in this thesis, Orebić is the one with the highest percentage of illegitimate births which is because of the different development and more open-minded society.