The study aimed to verify the psychometric properties of the 100-item HEXACO-PI-R questionnaire. The sample consisted of 1624 adults aged from 16 to 79 years (M=34.5, SD=13.35) who filled the paper-pen self-report form of the HEXACO-PI-R. The average internal consistency of the six factors was α=.78 (from .72 for Openness to .81 for Honesty-Humility) and α=.60 for facets. The Altruism scale in the Slovak translation did not reach a satisfactory internal consistency (α=.29). Mean values in the Slovak-speaking sample were 3.29, and standard deviations .53 for factor level and .74 at the facet level. Sex differences showed the higher Emotionality (d=.99) and Honesty-Humility (d= .38) in women. Age differences in Honesty-Humility showed a medium effect size. Factors did not inter-correlate, or they correlated weakly, except for r=.34 in the relationship between Agreeableness and Honesty-Humility. The factors were well distinguished from one another. The exploratory factor analysis with Promax rotation confirmed the six-factor model, which explained in total 44% of data variance, with an average loading of .60. Individual one-factor models met most of the goodness of fit criteria in confirmatory factor analysis, but the six-factor model did not meet them. The controversy associated with assessing the internal structure of multidimensional personality inventories by confirmatory factor analysis is discussed. According to the currently published research studies, the research findings supported the reliability and internal validity of HEXACO-PI-R in Slovak translation.