Sedentary behaviors in office workers has become a major public health concern and several initiatives have been proposed to break up sedentary behavior patterns during the performance of computer-intensive office work. Among such initiatives, the use of sit-stand workstations has been suggested to be one of the most promising by recent reviews. However, there still is only limited scientific evidence showing how effective sit-stand workstations are, in reducing sedentary behaviors and also documentation of their sustainability of use in studies of regular office work (i.e. as the “newness” of the system wears off, with time since introduction). This study aimed to document user behaviors and compare the use of two sit-stand workstation based interventions among two groups of administrative office workers: an “autonomous” group in which these workstations were introduced following some general ergonomic guidelines, and another “feedback-system” group in which the sit-stand tables were furnished with a semi-automatic reminder system, programmed to raise the table to a high (i.e. standing) position for 10 minutes after every accumulated 50 minutes of the table being in a low (i.e. sitting) position, i.e. to result in about 83% sitting per day. In addition, the sustainability of the use of these two kinds of sit-stand workstation interventions over two continuous months since their introduction was also studied. The results averaged over two months of usage of the two interventions showed that the percentage (%) sitting time was 87.4 (84.9-89.2) on average in the autonomous group and 84.0 (83.5-85.4) on average in the feedback-system group (P=0.001), and the frequency of switches between sitting and standing was 0.3 (0.2-0.3) per hour in the autonomous group and 0.7 (0.6-0.7) per hour in the feedback-system group (P=0.001). Thus, the sit-stand table system integrated with the automatic reminder system led to more reduction in sitting time and more switches in posture between sitting and standing as compared to the traditional sit-stand table, and behaviors of both groups were seen to be sustained over the 2-month intervention period (no difference across time for any of the variables tested for any group).