10.22376/ijpbs.2019.10.1.p1-12 Volume 8 Issue 4 2017 (October - December) Body positions can influence respiratory functions. Changes in body position can alter the length of respiratory muscle, namely diaphragm, thereby influencing its ability to generate tension. Recently, smartphones have become essential device in our daily life and people often demonstrate poor posture when using smart phone: To find out the effects of posture while using smart phones over pulmonary functions. Study design was non-experimental and the study type was observational. Sample size was 50 subjects. Inclusion criteria were both genders of age between 18-25 years, subjects who use smart phone for minimum 1 hour per day and exclusion criteria respiratory dysfunction, cardiac problems, spinal deformities, subjects involving in regular physical activity, smokers or if they had become non-smokers within the last 5 years, neurological disorders, spinal disc problems. Written informed consent of all the subjects selected were obtained. All the subjects underwent Pulmonary Function Test and FVC,FEV1,FEV1/FVC,PEFR were obtained as outcome measures. The values obtained were associated with various postures. The mean values of FVC (67.0125), FEV1 (69.1938) and PEFR (92.3813) in lying postures showed reduction when compared with that of other postures. The association of various postures with pulmonary function is not proved with FVC (p=0.247), FEV1 (p=0.113), FEV1/FVC (p=0.204) and PEFR (p=0.880) among smartphone users. In this study there is no significant changes in the mean values of PFT values for various postures among smartphone users. D. ANANDHI , ASWATHY.S , KEERTHIGA.L, V.P.R.SIVAKUMAR Pulmonary Function, smart phone users, posture, FVC, PEFR,FEV1/FVC. 471-477