The objective of the paper is to explore the relationship between participation in senior organisations and ways of ageing among older people. Moreover, the author focuses on determining whether the type of organisations (religious/non-religious) distinguish different groups of seniors in terms of lifestyle and perception of ageing. The analysis was conducted using data collected in 2013 and is available on www.diagnoza.com. The data concern Polish senior citizens (people aged 60 or over) who were selected at random. There were 9673 people, including 5586 women and 4087 men. Selected components of a senior lifestyle were used to illustrate the ageing process: (1) physical factors involving preventive healthcare and subjective health assessment, (2) psychological factors referring to feelings of happiness or loneliness (subjective assessment of one's own life), (3) social factors concerning relations with other people. Three senior citizen groups were compared, this comprised members of the organisations which promoted knowledge, members of religious organisations and non-members of such organisations. The analyses confirmed a hypothesis that participation in senior organisations is correlated with lifestyle and quality of life assessment. The type of organisations was found to be less relevant: organisations promoting knowledge as well as religious organisations appear to create learning environments which contribute to beneficial, optimistic self-perception of ageing. However, one can see the reflection on the assumptions underlying the activities of organisations as regards seniors' views on ageing.