Abstract Patriotism and nationalism as 2 types of attitudes have been used to interpret nation-related social behaviors, but whether they are mediated by distinct psychological and neural constructs remains unclear. We recorded rating scores and brain activities related to nationalism and patriotism statements that were dissected into affective (ie positive emotions pertaining to one’s own country or negative emotions pertaining to other countries) and cognitive (ie beliefs of the excellence of one’s own country or superiority of one’s own country over other countries) dimensions. Principal component analyses of the rating scores showed that the affective and cognitive components of nationalism vs. patriotism are disjointed to a larger degree. Functional magnetic resonance imaging results revealed that, while the right middle temporal cortex responded differentially to the affective and cognitive components of patriotism, a more extensive neural network, including the medial prefrontal cortex, lateral/orbital frontal cortices, insula, and temporal–parietal junction, responded differentially to the 2 components of nationalism statements. Moreover, the left frontal response to the affective nationalism statements mediated the link between nationalism-related emotions and behavioral tendencies to help other countries. Our findings unravel distinct psychological and neural constructs of patriotism and nationalism that advance our understanding of nation-related decision-making and behaviors.