[eng] A seasonal variation in demand is a well-documented phenomenon in tourism literature. Although there is a general agreement that certain characteristics influence the shape of the curve, there is no scientific theory on the seasonality of tourism. The purpose of this paper is to summarize the intra-year variation in arrivals to the Balearic Islands through the Gini-coefficient, providing evidence of the influence of some economic variables on the seasonal distribution of tourist numbers, using a regression analysis. The findings should assist in formulating new policy measures directed at achieving and maintaining a better distribution of the demand throughout the year, so as to maximize the benefits of tourism.