This paper refers to the topic of the importance of cultural training for an international assignment for the success of cultural adaptation of expatriates. The paper explains the importance of cultural training for the success of cultural adaptation of expatriates due to increasing globalization and the expansion of large companies beyond borders. International business is inevitable today. For this reason, expatriation has become an increasingly common phenomenon in every company. Recruiting new employees or sending existing ones on assignments abroad with the aim of increasing the success of the company. The main assumption is that expatriates must undergo certain cultural training in order to be successful at work. If the expatriates fail to adapt, there is a great possibility of negative work adaptation, that is, of the failure of the expatriate on an international assignment. The empirical research was conducted through a semi-structured interview with the participation of three expatriates who are currently on an international assignment in Croatia (the country of the subsidiary). Expatriates expressed their opinions about expatriation and their cultural adaptation very clearly. From their experience, one can see how much cultural training is needed for the success of cultural adaptation. In today's modern times, expatriation has become one of the key elements with which international human resources are faced and invest more and more resources in order for companies to operate as successfully as possible.