Sedentary behavior, or sitting, is a common health-related behavior in adults. Research has shown that prolonged sitting increases the risk of heart disease, type-2 diabetes and some cancers. Sit-to-stand workstations are becoming common in offices to help workers reduce their sitting time. This study examined time spent sitting at work, and after work, in office workers provided with sit-to-stand workstations for three months. The findings indicated that sitting time at work was reduced by 20 percent (a 1.5 hour reduction over an eight hour workday.) However, these individuals became slightly more sedentary after work. Despite this compensation effect, total daily sitting times were still lower when participants used sit-to-stand desks at work. Findings suggest that sit-to-stand workstations are a promising alternative to the traditional desk and chair, and could lead to substantial health benefits in sedentary workers. Further research is needed to examine the long term use of sit-to-stand desks on health.