In this study, the kinds of shares made by science teachers in a WhatsApp group as an online community of practice to support professional development were examined. The netnographic research method, one of the qualitative research methods, was used in the study. The messages shared by 12 science teachers, who worked at a private school between the years 2015-2016, in the WhatsApp group were examined in the study. Content analysis was applied to the data, and the themes were created. In the study, it was observed that teachers made shares in four different themes that support professional development. These were found to be shares for field knowledge, shares for pedagogical content knowledge, shares for in-school teaching practices and shares for emotional support among teachers. In this context, it was revealed that programs providing online chatting opportunities could be an important tool in ensuring the professional development of teachers.