The present invention relates to an aeration device (1) designed to aerate a grass strip, comprising a rotating shaft (2) which is provided along its length with a number of aerating blades (3) which are at right angles to the shaft and designed to loosen and remove parts of the grass strip, a guide device (4) for collecting the material loosened by the aerating blades (3) and discharging it in the direction of a collecting device (5), in which said guide device (4) comprises lower and upper guide means, which can be rotated in opposite directions to one another, and in which the lower guide means comprise at least three spaced-apart lower roller bodies (6a1; 6a2; 6a3; 6a4) as a result of which the loosened material it at least sieved while it is being discharged before it is compacted between a lower roller body (6a4) and a pressure-exerting roller (6b).