Although activity trackers are becoming more popular, little is known whether this new technology qualifies to improve employees' health. This study aimed to evaluate the effect of a workplace intervention applying activity trackers (behavioral approach) along with an online coach (cognitive approach) on work-related well-being (e.g., burnout) and physical health (e.g., body mass index). To test for intervention effects, 116 employees at risk were recruited at 1 large mobility enterprise in Germany and randomly assigned to an intervention group (n = 59) and a control group (n = 57). Intervention effects were assessed 1 month, 3 months, and 1 year after the intervention. Analyses of variance for repeated measures revealed no intervention or long-term effects on work-related well-being. In the intervention group, we found a significant increase in health perception and a significant decrease in body mass index. These effects were stable over time 3 months after the intervention for health perception and 1 year after the intervention for body mass index. Our study shows that a cognitive-behavioral intervention with activity trackers improved physical health over time but was not effective in enhancing work-related well-being. (PsycInfo Database Record (c) 2020 APA, all rights reserved).