New instruments are described for the measurement of both job-related and non-job mental health. These cover two axes of affective well-being, based upon dimensions of pleasure and arousal, and also reported competence, aspiration and negative job carry-over. Baseline data are presented from a sample of 1686 job-holders, and earlier uses of the well-being scales are summarized. The instruments appear to be psychometrically acceptable, and are associated with demographic and occupational features in expected ways. For example, older employees report greater job-related well-being; occupational level is positively correlated with job depression-enthusiasm but negatively associated with job anxiety-contentment; depression-enthusiasm is more predictable from low-to-medium opportunity for skill use and task variety, whereas anxiety-contentment is more a function of workload or uncertainty.