Economic downturns and organisational changes have stimulated studies on the importance of job security for public employees; however, there has been some disagreement as to whether job insecurity should be defined using a single- or a two-factor model, on how to measure it and which antecedents and consequences are linked to it. Questionnaires measuring job insecurity as well as personality traits and job characteristics as possible antecedent variables, and job performance and job satisfaction as possible consequences were completed by a sample of 71 federal government employees during recent important government downsizing. A multiple regression analysis indicated that job insecurity, defined as a combination of organisational or personal vulnerability, was significantly related to only two antecedent variables, i.e., Neuroticism and job characteristics. Further regression analyses indicated that job insecurity was a statistically significant moderator but only between one consequence, i.e., intention to quit, and the job characteristics variable. These results along with methodological issues and further research, are discussed.