Although the benefits of nature exposure to human health are well documented, less is known about the psychological benefits of exposure to nature indoors. This study observed whether the addition of greenery to a workplace setting improved psychological well-being and performance of employees. A crossover study among 63 adults examined perceived psychological well-being and objective memory task performance with and without indoor greenery present in an open workplace setting. Statistical analyses indicated that there was only a marginally significant increase in memory task performance with the presence of plants. However, participants showed slightly better psychological well-being without the presence of plants when compared to performance with plants, on both floors. Study results suggest that the presence of windows, natural light, and high ratings of perceived psychological health may have confounded the effects of plant presence.