An experiment was conducted at Cotton Seed Multiplication, Training and Research Farm, Sreepur, Bangladesh during August, 2016 to January, 2017 to evaluate the response of cotton plant height to different plant spacings and time of application of mepiquat chloride (MC) growth regulator. Five plant spacing like 60 cm × 30 cm, 60 cm × 40 cm, 75 cm × 30 cm, 75 cm × 40 cm and 90 cm × 45 cm; MC spray @ 1.0 ml L-1 water at 25, 50, 75, 100 and 125 DAE along with water spray as control, were considered as the treatments of the experiment. Plant spacing of 60 cm × 30 cm showed the lowest values of cotton plant height (91.59 cm) whereas MC application, 1MC L-1 water at 25 DAE gave shortest plant height (81.41 cm).  Plant spacing of 60 cm × 30 cm along with foliar application of 1ml MC L-1 water at 25 DAE gave significantly minimum plant height (86.64 cm) as compared to control treatments having conventional wider spacing of 90 cm ×    45 cm.  So, 1 ml MC L-1 water at 25 DAE with 60 cm × 30 cm spacing treatment combination could be practiced for profitable cotton production at Sreepur, Gazipur areas of Bangladesh. 

Key words: MC, spacing, foliar application and plant height.