It has been argued that older people's civic engagement has benefits for both individuals themselves and the community more broadly. Removing barriers to participation is, therefore, essential. However, the multi-dimensional nature of civic participation, as well as the different issues raised by recruitment and retention, complicate this. This study explores the barriers to retention of Spanish older people in political organisations, as one important type of participation that has received little attention in the literature to date. A total of 192 people aged 65 and over and actively engaged in three kinds of political organisation participated in this study. Participants answered an open-ended question regarding perceived barriers to continued involvement. Results show a range of reasons for potential future disengagement from political organisations. These barriers fit into three overarching categories related to changes in means, motives or the opportunity context for participation. Means-related barriers were by far the most frequently identified type of barrier. Both the type of organisation and some socio-demographic and participatory characteristics have an impact on the reasons respondents indicated they may potentially stop participating in future. Results suggest the necessity of a more nuanced and multi-faceted approach to understanding barriers to participation. Particularly, the development of retention strategies by political organisations should take into account the specific characteristics of the individuals and organisations they are targeting.