From their origins, Italian early childhood services paid attention to the transition from family to childcare centre, explicitly referring to attachment theory. In the present study, the "Parent Attachment Diary" was adapted and applied within a childcare centre context to examine the development of infants' relationship with their professional caregivers during the earliest months of attendance. The research focuses on two studies, using the adapted version of PAD, the "Professional Caregiver Attachment Diary" (PCAD). The two studies involved a total of 87 professional caregivers and 222 infants aged between 4 and 35 months (M = 16 months). After both 2 and 4 months after starting the childcare centre, children show a significant decrease of "Avoidant" and "Resistant" attachment behaviours, but "Secure" behaviours do not increase over time. However, behaviours coded as "Non Distressed" significantly increase, which could indicate children feel more secure in the new setting of care over time. These results demonstrate the utility of the PCAD to describe the "process" of adaptation in the new context.