Mentally challenged individuals are known to have slower speed of reaction. As a previous study has shown immediate improvement in reaction time (RT) following mukha bhastrika, a bellows type of pranayama, we planned to study the effect of this pranayama in mentally challenged adolescents. 34 mentally challenged adolescents (15.1±0.806 y) studying in a school for Special Needs were recruited as they have been receiving yoga training once a week for more than 3 years. Exclusion criteria were inability to either perform mukha bhastrika or to understand procedure for testing RT. Visual (VRT) and auditory reaction time (ART) was measured using RT apparatus before and after nine rounds of mukha bhastrika and a control period of ten minutes of normal activities to rule out any test-retest practice effect. Analysis of non-intervention period values showed that the reliability in terms of reproducibility of the observation for both VRT (r=0.87) and ART (r=0.95) was excellent. Mukha bhastrika produced an immediate and significant decrease in both VRT and ART. There was a statistically significant decrease in VRT (P<0.0001) from 296.15 ms±13.49 to 263.59 ms±12.53 and ART (P<0.0001) from 247.88 ms±14.33 to 217.35 ms±11.36 following mukha bhastrika. Decrease in RT signifies improved central neuronal processing ability. This may be due to greater arousal and faster rate of information processing, improved concentration and/or ability to ignore or inhibit extraneous stimuli. Mukha bhastrika may be altering afferent inputs from abdominal and thoracic regions, in turn modulating activity at ascending reticular activating system and thalamo-cortical levels. It is suggested that yogic breathing techniques like mukha bhastrika be used as an effective means of improving neuromuscular abilities in special children.