This research proposes a novel account for the established benefits of nature on psychological well-being from the perspective of Self-Determination Theory. That is, nature enhances psychological well-being by satisfying the basic psychological needs of autonomy, competence and relatedness. Compared with non-nature control settings, two field experiments consistently showed that participants who were exposed to nature scenes manifested higher levels of positive affect, life satisfaction and meaning in life; and satisfaction of the three psychological needs mediated these nature effects. Three laboratory studies replicated these findings by exposing participants to digital nature scenes (vs. non-nature ones) or indoor plants (vs. control setting without indoor plants) or engaging them in nature-related activities (vs. non-nature related ones), with the exception of a non-significant effect of nature on satisfaction of relatedness. Taken together, these studies provided convergent evidence for our proposition, shedding light on the mechanisms underlying the benefits of nature on psychological well-being. • We propose that nature can enhance psychological well-being by satisfying three basic psychological needs for autonomy, competence and relatedness as suggested by Self-Determination Theory. • Two field studies and three laboratory experiments confirm the effects of diverse nature (natural environments, nature pictures, indoor plants and nature-related activity) on psychological well-being. • Further, nature's positive effects can be mediated by fulfillment of three basic psychological needs ( Deci & Ryan, 1985 , 2000 ; Ryan & Deci, 2017 ).