Quinoa (Chenopodium quinoa Willd.) quickly adapts to different climatic conditions; however, low soil fertility conditions and inadequate soil water levels may reduce yield. The objective of this study was to evaluate the effect of irrigation levels and potassium fertilization for quinoa production in the Cerrado Oxisol. The experiment was performed in a greenhouse, located at the Federal University of Mato Grosso (UFMT), Campus of Rondonópolis -Brazil, using soil collected from a Cerrado Oxisol. The experimental design was a randomized complete block design in a 5x5 factorial scheme with four replicates, corresponding to five potassium doses (0, 100, 200, 400 and 600 mg dm -3 ) and five irrigation levels (50, 75, 100, 125 and 150% of field capacity). The variables of dry mass of shoot, dry mass of roots, water use efficiency, mass of 100 grains, production and number of grains were analyzed. The dry mass of the aerial part and the roots are influenced by the potassium fertilization in the doses between 530 and 600 mg dm -3 . All the vegetative and productive characteristics were affected by the treatments. The highest water use efficiency was observed at the potassium (K 2 O) dose of 375 mg dm -3 and a 50% irrigation level.