Objectives: The study examined whether transition to retirement was associated with changes in social networks and social participation, and whether these changes differed by gender, partnership status or European region.

Methods: Data were derived from fourth and sixth rounds of the Survey of Health, Ageing and Retirement in Europe (SHARE), collected with a 3–5-year interval from 14 European countries. The sample involved 12,885 individuals aged 50–79 (mean age 58) at the initial timepoint. Fixed-effects regression models were used to estimate within-person changes over time.

Results: The results showed changes in the size and composition of social network, contact frequency with close network members, and the intensity of social participation. The most consistent change was a decrease in the presence of colleagues within the close network. By contrast, the number of relatives in the network, total frequency of social contacts, and satisfaction with the close network remained rather stable.

Discussion: The retirement transition is associated with predominantly positive changes in social relationships. While relationships with colleagues fade, they are compensated by other close connections or intensified social participation, or both. However, the patterns of change vary substantially across sub-populations and geographic regions. Interaction with relatives remains mostly unaffected by retirement, demonstrating the resilience of these relationships to contextual changes.