The seed counting sensor (200) for pneumatic seeding machines comprises a detection chamber (210) within a house (204), said detection chamber allowing the seeds to pass through the sensor and having a center axis (211) extending in the flow direction of the seeds (102)； a plurality of light sources (240) arranged within the house (204), outside the detection chamber (210), at predetermined distances from each other, said light sources being in a plane (P) extending substantially perpendicularly to said center axis of the sensor； a plurality of light detectors (250) arranged within the house (204), outside the detection chamber (210) at predetermined distances from each other, said light detectors being in the same plane (P) as the light sources, wherein the number of the light detectors equals to the number of the light sources, and a signal processing unit (502) for controlling operation of the light sources (240) and for processing the electronic signals produced by the light detectors (250).
