This paper investigates whether Reciprocal Peer Observation is an effective practice for promoting Teacher Professional Development. It focuses on analysing the Improvement Goals transfer processes stemming from teachers' own educational approach, which teachers identify during Reciprocal Peer Observation. A total of 230 teachers, paired together, conducted a second classroom observation, focused on a specific Improvement Goals to assess the extent of their transfer. The findings indicate that Improvement Goals transfer to classroom practice occurs predominantly. The study analyses predictive and facilitating factors that contribute to this process. The results reveal that collaborative culture and collective agency are predictive factors for transfer. Similarly, personal factors arising from reflection and awareness of one's own practices, alongside the support of the partner, could promote the identified processes of improvement. In conclusion, Reciprocal Peer Observation can be regarded as a highly effective practice for identifying Improvement Goals and transferring them to the classroom, benefiting Teacher Professional Development.