Objective: The aim of this study was to investigate the use of stairways/moving stairways in shopping malls and examine the extent to which simple warning signs determined whether people took the stairs. Design: Large posters that could readily be seen by mall visitors were situated between the stairs and moving stairways in shopping malls. Setting: A total of 30,026 people who visited the shopping mall over an 11 week period were chosen consecutively for this study. Method: Thirty-three counting operations (2 h/day) were undertaken using two positive posters and one negative poster on different days of the week. In the process of counting, four groups were examined: children, adults aged <55 years, adults aged =55 years, and overweight individuals. General observations conducted during the first 2-week period, and the 5th, 8th, and 11th weeks served as control periods. Results: When posters were not shown, rates of stair use were lower among individuals in all age groups, but the ratio of stairway to moving stairway use tripled when positive-direction posters were displayed. Similarly, negative-direction posters decreased the ratio of stair to moving stairway use. Positive-direction posters were strongly associated with stairway use (p = 0.001). Conclusion: This study showed that the use of stairs decreased when no poster was displayed, while positive posters increased stair use and negative posters decreased this behaviour. Individual preference, together with the comfort brought by moving stair technology, consciously or unconsciously causes individuals to avoid activities they can perform during the day.