The rapid development of generative artificial intelligence (AI) is expected to have a profound impact on various aspects of human society, including mathematics education. Nevertheless, there is a noticeable lack of research, particularly in Greece, that focuses on the development and assessment of lesson plans and math worksheets tailored for students with special educational needs. To address this research gap, we designed and conducted a nine-hour teaching intervention in a general mathematics classroom in Greece, involving two 8<sup>th</sup> grade students with special educational needs as the subjects of the study. The intervention utilized worksheets generated by the ChatGPT 3.5 application, which were customized based on the current curriculum, as well as the special educational needs and interests of the two participating students. The data were collected through interviews, tasks, and e-questionnaires, and analyzed using a new theoretical framework based on the concept of mathematical familiarity. The results indicated that students were actively engaged in the educational process, felt safe and confident, satisfactorily met the learning objectives, and developed positive attitudes towards the mathematics course. The paper concludes with a list of good practices, teaching suggestions and restrictions that could be useful to teachers and education policy makers. The target audience for the current study is, mainly, mathematics teachers who serve at all levels of education and have students with special educational needs in their classrooms. Furthermore, the article may also prove of interest to students, parents and teachers who are interested in the interaction between mathematics education and generative AI.