People with high emotional intelligence (EI) understand themselves and others well, and perform well at work. Trait EI has been described as “a constellation of emotion-related self-perceptions and dispositions” (Petrides and Furnham 2006), and can be measured by the Trait Emotional Intelligence Questionnaire Short Form (TEIQue-SF). The aims were to validate the Swedish version of TEIQue-SF by (1) investigating its internal consistency; (2) exploring its relationships with “Big Six” and “Dark Triad” personality traits as well as with self-perceived individual work performance; and (3) identifying which personality traits best explain variations in Trait EI, and whether this trait can predict variations in work performance over and above personality traits. Multi-occupational employees in Sweden (N = 228; M = 34 years, SD = 12.6, range 16-71 years, 66% women) with an average work experience of 14 years (SD = 11.5) were surveyed. In line with past research, internal consistency of TEIQue-SF was good, for the global Trait EI scale score (.86), and for one of its subdimensions (Well-Being) (.81). Global trait EI scale score and its subscales correlated negatively with Neuroticism and Machiavellianism, and positively with Extraversion, Agreeableness, Conscientiousness, Openness to Experience, and Narcissism. Sociability and Self-Control had, however, almost zero correlations with Machiavellianism. All subscales of global trait EI scale score correlated positively with Task Performance and Contextual Performance. On separate regression analyses, Big Six traits explained 48%, and Narcissism 14%, of the variation in global trait EI scale score. Trait EI accounted for a significantly larger proportion of the variation in Contextual Performance than any of the Big Six traits, and an additional 6% of the variation in Task Performance when controlling for gender, age, Neuroticism and Conscientiousness. The Swedish version of TEIQue-SF has good reliability as a global trait EI scale, reasonably theoretically and empirically grounded relationships with relevant variables for the workplace, and incremental validity over and above Big Six traits in predicting work performance in younger people with relatively high educational levels. Its reliability on the subscale level and its item functioning need to be further investigated in more heterogeneous samples.