Background:Formaldehyde is a common hazardous indoor air pollutant which recently raised public concerns due to its well-known carcinogenic effects on human. The aim of this study was to investigate a potted plant-soil system ability in formaldehyde removal from a poor ventilated indoor air to promote dwellers health.Methods:For this purpose, we used one of the common interior plants from the fern species (Nephrolepis obliterata), inside a Plexiglas chamber under controlled environment. Entire plant removal efficiency and potted soil/roots contribution were determined by continuously introducing different formaldehyde vapor concentrations to the chamber (0.6–11 mg/m3) each over a 48-h period. Sampling was conducted from inlet and outlet of the chamber every morning and evening over the study period, and the average of each stage was reported.Results:The results showed that the N. obliterata plant efficiently removed formaldehyde from the polluted air by 90%–100%, depending on the inlet concentrations, in a long time exposure. The contribution of the soil and roots for formaldehyde elimination was 26%. Evaluation of the plant growing characteristics showed that the fumigation did not affect the chlorophyll content, carotenoid, and average height of the plant; however, a decrease in the plant water content was observed.Conclusions:According to the results of this study, phytoremediation of volatile organic compound-contaminated indoor air by the ornamental potted plants is an effective method which can be economically applicable in buildings. The fern species tested here had high potential to improve interior environments where formaldehyde emission is a health concern.