Background: Introduction of sit-stand tables has been proposed as an initiative to decrease sedentary behavior among office workers and thus reduce risks of negative cardiometabolic health effects. However, ensuring proper and sustainable use of such tables has remained a challenge for successful implementation. Objective: We developed a new system to promote and sustain the use of sit-stand tables. Methods: The system was programmed to change the position of the table between “sit” and “stand” positions according to a regular pre-set pattern, if the user agreed to the system-generated prompts prior to each change. The user could respond to the system-generated prompts by agreeing, refusing or delaying the changes by 2 minutes. We obtained user compliance data when this system was programmed to a schedule of 10 minutes of standing after every 50 minutes of sitting. Compliance was investigated in nine office workers who were offered the semi-automated sit-stand table for two months. Results: On average, the system issued 12-14 alerts per day throughout the period. Average acceptance rate ranged from 75.0-82.4%, and refusal rate ranged from 11.8-10.1% between the first and eighth weeks of intervention (difference not statistically significant). During the first week after introduction, the table was in a standing position for 75.2 min on average, increasing slightly to 77.5 min in the eighth week. Conclusion: Since the workers were essentially sitting down before the table was introduced, these results suggest that the system was accepted well, and led to an effective reduction of sitting during working hours. Users also reported that the system contributed positively to their health and wellbeing, without interrupt their regular work, and that they would like to continue using the sit-stand table even beyond the two-month period, as part of their regular work. Compliance beyond two months of use, however, needs to be verified.