Effect of microbiological fertilizer (Slavol) and soil additives (zeolite and hydrogel) on buckwheat (Fagopyrum esculentum Moench) yield was investigated in this paper. Trial was set up in the village of Radijevići, Serbia in agroecological conditions of mountain Zlatar (altitude 1,065 m) during a two-year period 2009 and 2010. A randomized complete block design with four replications was set up. In organic cropping system three combinations of microbiological fertilizer (Slavol) with zeolite and hydrogel were used prior to sowing. Different combinations of the microbiological fertilizer and the soil additives gave positive results especially in the second year of the trial. The best combination in organic cropping system was Slavol+hydrogel with foliar application of the microbiological fertilizer, which resulted in the greatest yield of buckwheat and this treatment can be recommended to producers. Buckwheat performed very well under limited conditions of acidic soil on high altitude in organic cropping system and it can be recommended as a very suitable crop for organic producers.