The present paper analyses the seasonal concentration on the Andalusian coastline, a Spanish Mediterranean coastal destination characterised by its high seasonality in the summer months. The analyses were conducted by separating tourists according to their main travel motivation, and distinguishing sun and sand tourists from cultural and other segments tourists, based on their place of origin and on the coast they visited. The quantitative tools applied included the additive decomposition of the Gini index and the calculation of the relative marginal effects. The proposed methodology serves as a useful tool for tourism managers and administrators interested in reducing seasonality, since it facilitates the identification of tourists segments that can effectively contribute to the reduction of seasonal concentration. Among the main results for the studied area, it was found that given the heterogeneity of the groups of tourists (both domestic and foreign), it was much more effective to separate tourist segments by their main travel motivation. The cultural segment was the most favourable for deseasonalisation, especially within domestic tourists, since with foreigners the same deseasonalising effect was not present in all the coasts analysed.