This research aim is to study the factors affecting the mechanical planting of coated quinoa seeds. The tested parameters of mechanical planting of coated quinoa seeds are metering-device and forward speeds on seed damage and discharge, seed germination and emergence, missing hills and double plants percentage, planter ground-wheel slip and quinoa-seed yield. The main results in this study can be summarized in the following points: The maximum quinoa coated-seed discharge of 5.50 kg/feddan (feddan = 4200 m² = 0.420 hectares = 1.037 acres) was obtained with a metering-device speed of 20 rpm. Meanwhile, the minimum quinoa coated-seed discharge of 3.10 kg/feddan was obtained with a metering-device speed of 60 rpm. The maximum quinoa plant-emergence of 75.6 % was obtained with a forward speed of 1.82 km/h. Meanwhile, the minimum quinoa plant-emergence of 63.6 % was obtained with a forward speed of 4.79 km/h. By increasing forward speed from 1.82 to 4.79 km/h the total quinoa seed yield decreased from 850 to 650 kg/feddan.