Psychological and other factors are examined individually and collectively in relation to self-perceived chronic fatigue among a national sample of adults. It is found that the lifestyle variable physical activity and such psychological variables as self-reported depression, anxiety, and emotional stress are highly associated with fatigue and are independently predictive of it. Adults who are physically inactive or who experience any psychological problems are at much higher risk of feeling fatigue than those who are physically active or free from psychological problems. Women are more likely to feel fatigued than men, and heavier women are more likely to feel fatigue than lighter ones. No difference in degree of fatigue was found between heavier and lighter men.