The aim of this paper is to analyze the psychometric properties of a short version of the “Positive and Negative Affect Scale” (PNA; Warr, Barter and Brownbridge, 1983). The participants were 1601 individuals (61.6% women) with a mean age of 33.27 years. Confirmatory factor analysis evidenced better indicators of adjustment for a reduced version of the instrument (PNA-10) composed of 10 items. The internal consistency (Cronbach’s alpha) of the subscales was adequate: .84 for PA and .81 for NA; composite reliability of .88 for PA and .82 for NA. Further analysis showed significant relationships of PA and NA with sex, marital status, length of the relationship and number of children, and also with loneliness (social, family and romantic). These results, as well as the low correlations of the instrument with Social Desirability, confirmed the good psychometric properties of PNA-10, which we consider to be an appropriate instrument for assessing the emotional component (PA and NA) of subjective well-being.