Researchers are increasingly turning their attention to the assessment of wellbeing at work through the use of valid and reliable scales, especially based on the growth of studies on Positive Psychology. This study examines the evidence of validity and reliability of the Well-being at Work Scale of Paschoal and Tamayo (2008). This instrument is composed of the following factors: positive affect, negative affect, and fulfilment/personal expression. Principal axis factoring, with 169 valid cases, indicated the extraction of 3 factors, which together account for 62.55% of the total variance. Exploratory factor analysis pointed to the same factorial structure as the original scale and all items significantly represent each factor. The scale presented high levels of internal consistency and good psychometric parameters, which can be useful for organizational diagnosis and planning of actions in human resources. The scale serves to identify the most harmful aspects and those that contribute to well-being, providing important information to support future interventions that can alleviate the negative affects and the perception of lack of accomplishment at work.