An experiment was conducted to study the effect of plant spacing on herbaceous yield and oil yield of peppermint (Mentha piperiata L.) in Zalingei during 2018. Four levels of spacing were assigned to complete randomized plot design with four replications. Data on fresh leaf yield, dry leaf yield, fresh aboveground biomass yield, dry above-ground biomass yield essential oil (EO) content and EO yield were collected and analyzed. Row spacing significantly influenced all the parameters except for fresh leaf/stem ratio, dry leaf/stem ratio and EO content during the experiment. Row spacing affected fresh leaf yield, fresh above-ground biomass yield, dry above-ground biomass yield, significantly (P < 0.05) and dry leaf and EO yield highly significantly (P < 0.01). Fresh leaf and EO yield varied from 3,650.9-10,882.1 and 10.2-18.8 kg/ha, respectively and maximum values were obtained at the harvesting age of 120 days after planting at first harvest. Maximum yield of 62.89 kg/ha fresh leaf obtained with 10 cm row spacing and 0.50 kg/ha EO was obtained with a 40-cm row spacing and not significantly different with 10 cm row.