With the objective to determine the range of moisture content for mechanical harvesting of soybean seeds without compromising physical quality and without high losses during harvest, having in mind harvesting with high moisture, seeds at 11.4 to 22.7% moisture content were harvested. The following cylinder rotations were used: 450, 550 and 700rpm for 11.4% moisture content and 600, 700 and 800rpm for the other moisture levels. There was used opening width between concave and cylinder of 18mm. The evaluations were: a) mechanical damage, using the tetrazolium test (category 6 to 8) and injury in 0.25% sodium hypochlorite; b) number of split seeds/500g; c) percentage loss during harvest. According to the results, seeds harvested at moisture contents between 14.0 and 18.0% showed less mechanical damage and the lowest loss during harvest. On the other hand, moisture contents between 11.4 and 19.0% showed an acceptable damage and the loss was still below 3.0%. The most severe mechanical damage occurred by combination of low moisture contents at harvest with high cylinder rotations and when the moisture contents at harvest were above 19.0%.