Previous studies on ageing consumers have mainly focused on chronological age and generational values or studied ageing and consumption with cross‐sectional data. Few quantitative studies exist that examine the effect of age together with life course on consumption using longitudinal data. To bridge this gap, the article examines ageing and attitudes towards consumption in Finland, focusing particularly on late middle‐agers (46–60 year‐olds) in comparison with young adults (18–30 year‐olds) between 1999 and 2014. The article explores three consumption patterns based on attitudinal statements: ecological, economical and self‐indulgent consumption. Through analysis of a nationally representative survey study in Finland (N = 8,543), the article reveals that in all years under examination, late middle‐agers reported more ecological attitudes towards consumption than young adults. In 1999 and 2004, the attitudes of late middle‐agers appeared more economical, but age‐related differences in economical attitudes disappeared between 2009 and 2014. In each year, late middle‐agers reported less self‐indulgent attitudes than young adults, and these age‐related differences did not remarkably change between 1999 and 2014. The results indicate that in 1999 and 2004, ecological and economical attitudes towards consumption were best predicted by age at the year of the study. In later years, ecological attitudes were more closely determined by life course stage, that is household type and other socio‐demographic determinants. Regarding economical attitudes, generational or cohort effects were pronounced among late middle‐agers in 1999. In contrast, the significance of age remained throughout the years for self‐indulgent attitudes, indicating the absence of generational or cohort effects.