aiming to evaluate the effect of k2o levels on the increase of snap bean yield, an experiment was performed in paraíba state, brazil, in a quartz psamment soil. the experimental design was of randomized blocks, with six treatments (0; 50; 100; 150; 200 and 250 kg ha-1 of k2o), in four replications. each plot contained 40 plants spaced 1.0 m x 0.2 m. pods maximum number/plant (20 pods) and the maximum yield/plant (171 g), were obtained, respectively with 145 and 173 kg ha-1 of k2o, and pods yield reached maximum value around 25,3 t ha-1 at the level of 171 kg ha-1 of k2o. the most economic level of k2o for the production of pods was of 165 kg ha-1. the most economic level represented 96% comparing to that responsible for maximum pods production. the k2o levels that obtained maximum pods production and economic return were correlated, respectively, with 181 and 176 mg dm-3 of k available for the extractor mehlich 1.