Psychological stress can cause decreases in well-being, increases in disease, and faster cellular death. Because the workplace is one prominent source of stress, it is both practically and theoretically useful to comprehensively understand which workplace practices may be stress-inducing. In two experiments, we found that people nudged to be in an “economic mindset” (who thought of time in terms of money while working on a realistic “at work” task) self-reported higher levels of psychological stress (Experiments 1 and 2) and also evidenced more physiological stress — levels of salivary cortisol were 23.53% higher (Experiment 2) — compared to participants whose monetary value of time was not made chronically salient. We suggest several possible mechanisms through which the economic evaluation of time may cause stress. A commodified view of time can increase impatience and make someone feel pressured to “use time wisely”. And thinking of time like money can diminish the meaning of a person’s work and psychological attachment to the job, thereby making tasks more stressful. Thus, increasingly common work arrangements that commodify time may increase stress.