The aim of the study was to investigate if years of running experience influence the motivations of marathon athletes. An empirical study was conducted during the last (20th) PKO Poznan Marathon, one of the largest and most popular mass running events in Poland, which was held in Poznan (Poland) in October 2019. A total of 493 marathon runners (29% of whom were female, and 71% of whom were male) took part in the cross-sectional study, which used the diagnostic survey method. The questionnaire employed the division of motives from the motivation of marathoners scale (MOMS) by Masters et al., adapted to the Polish language by Dybala. Running motivations have already been analysed for variables such as age, gender and place of residence, but there is a research gap regarding existing research, as the relationship between motivations and running experience has not yet been studied. One-way analysis of variance for independent samples was used to verify statistical hypotheses. Prior to making the relevant calculations, the assumption of homogeneity of variance was checked via Levene’s test. Variances were assessed with an F-test, and if they were unequal, Welch’s correction was applied. Eta squared (η2) was used as a measure of effect size. The calculations carried out showed that running experience was not a statistically significant factor in the motivations of runners taking part in a marathon.