Refugees, asylum seekers, and other vulnerable migrants make a specific, increasingly growing category of foreign language learners, which brings about dynamic changes in established language teaching contexts and the expected skills of language instructors. Traditional institutional teaching within curricula and modules is being replaced by informal, non-standard, and improvised contexts of language teaching aimed at the specific needs of these vulnerable learners. In Croatia, volunteer language teaching is one of many indispensable forms of support for refugees and typically occurs due to a lack of available language courses designed for the specific needs of these learners, or as an ad-hoc activity emerging from their everyday needs. Oftentimes, volunteer language instructors are not certified or experienced language teachers, and apart from participating in short informal workshops and seminars, they are not formally equipped to work with such vulnerable learners. Appropriate teacher qualification is seen as one of the fundamental prerequisites of successful teaching, particularly in contexts where learners have different cultural backgrounds, experiences of prolonged trauma, lower education levels and literacy challenges, or have no knowledge of the (Latin) alphabet. Therefore, besides linguistic knowledge and teaching method skills, teaching vulnerable groups requires a high level of intercultural competence and understanding of the principles of inclusive teaching. This paper presents findings from a study conducted among 28 participants, who are volunteer teachers of Croatian for refugees in various contexts. The study demonstrates volunteers’ attitudes about teaching Croatian to refugees, the perception of their role in this process, and their attitudes about the competencies necessary for this type of language instruction. Results show that the majority of respondents do not consider formal credentials and certifications necessary for successful teaching but that having them is a valuable asset. Respondents identify external organizational problems such as the difficulty in organizing continuous teaching or the lack and decline in learner motivation as the main problems of their teaching experience. They mention challenges such as the complexities of the Croatian language and lack of appropriate teaching materials, as well as the lack of continuous, free, and available language courses for refugees.