An experiment aims to improve the organic production of kohlrabi using algae extract and biofertilizer was conducted at the experimental farm of Central Laboratory for Agricultural Climate, Agricultural Research Center, Giza, Egypt, during two successive seasons of 2018/2019 and 2019/2020. Treatments were compost only, compost with adding biofertilizer and algae extract individually or in combination, and were applied on two kohlrabi cultivars (Gulie White Vienna and Delikatess Purple Vienna). The results indicated that “Gulie White Vienna” cultivar was superior to “Delikatess Purple Vienna” in vegetative growth, nutrition content, knob yield and knob properties. All treatments of biofertilizer and algae extract individually or in combination in the presence of compost improved all studied traits compared to compost only. Applying compost with adding biofertilizer and algae extract in combination recorded the highest values of growth, nutrition content, yield and knob properties. This study demonstrated the possibility of using biofertilizer and algae extract in addition to compost for organic production of kohlrabi and for improving yield and knobs quality.