The article deals with the study of relationship of the level of personal machiavellianism and the subject's tendency to fib in the situations of interpersonal communication. Three hypotheses have been proved: 1) people, inclined to fib, in experiments show high marks by machiavellianism scale; 2) they have a relatively low level of selfrespect and low selfesteem of moral qualities of personlity by "Personality differential", low marks in altruism factor of Liri's method and, on the contrary, high marks in suspiciousness factor; 3) in women's personality structure machiavellianistic attitudes and abilities are less expressed than those in men's, therefore the psychological basis of understanding of fib situations are primarily different in women and men.