The transition to retirement is a crucial status passage in older adults’ life. To date, little is known about the consequences of this transition for the quality of private relationships in Germany. Therefore, the aim of this study is the examination of conditions under which a positive development of social relationships in family and friends after the transition to retirement is possible. 1,949 retirees aged 55 to 70 years (M=66.2) were asked about subjectively experienced changes in their relationship to their partner, children, grandchildren, and friends since the transition to retirement. By means of an index, improvement and deterioration in all four dimensions were measured, displaying different conditions. A stepwise linear regression analysis shows the influence of activity-related factors, individual and socio-economic characteristics, interaction effects of activities and gender, as well as the type of retirement transition. Caring for grandchildren especially shows a positive correlation with an increased quality of private relationships. Those who realize active and planning life investment also hold a more positive perception of close social relationships since the transition to retirement. Besides, men who do not work after retirement experience a higher quality of close relationships than those men who perform bridge employment. An involuntary retirement transition shows a negative correlation with perceived relationship quality.