The present invention concerns an aeration system for shoes comprising an aeration device, specifically pumping means like a bellows pump, which constitutes a further object of the invention. More specifically, the present invention concerns an aeration system for shoes, comprising a hollow sole (1) having an aeration device in fluid communication both with the inside of the shoe and with the outside, at least one first and a second cavity (2, 3) being formed inside said hollow sole (1), pumping means (9) being housed in said at least one first cavity (2), wherein said pumping means (9) comprise a shell (10) and a distribution nozzle (11), a flexible core (12) being housed inside said shell (10), and a pad (18) is housed in said second cavity (3).